Exterior rearview mirror assembly

ABSTRACT

An exterior rearview mirror assembly includes a variable reflectance mirror reflective element. A mirror reflector of the mirror reflective element includes a stack of thin films having at least two thin films. At least one of the thin films is formed of a material that has a specific resistivity of less than about 1×10 −2  ohm·cm, and at least one of the thin films is a thin metal film. An electrochromic medium is disposed in an interpane cavity of the mirror reflective element and is bounded by a perimeter seal. A reflective perimeter layer is disposed at a second surface of a front substrate proximate a perimeter edge of the front substrate. The perimeter layer generally conceals the perimeter seal from view by a driver of the vehicle normally viewing the front substrate when the exterior rearview mirror assembly is mounted at the vehicle.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent application Ser. No. 12/979,492, filed Dec. 28, 2010, now U.S. Pat. No. 8,335,032, which is a continuation of U.S. patent application Ser. No. 12/727,691, filed Mar. 19, 2010, now U.S. Pat. No. 7,864,399, which is continuation of U.S. patent application Ser. No. 12/429,620, filed Apr. 24, 2009, now U.S. Pat. No. 7,710,631, which is a continuation of U.S. patent application Ser. No. 11/956,893, filed Dec. 14, 2007, now U.S. Pat. No. 7,525,715, which is a continuation of U.S. patent application Ser. No. 11/709,625, filed Feb. 22, 2007, now U.S. Pat. No. 7,310,177, which is a continuation of U.S. patent application Ser. No. 10/533,762, filed May 4, 2005, now U.S. Pat. No. 7,184,190, which is a 371 application of PCT Application No. PCT/US2003/035381, filed Nov. 5, 2003, which claims priority of U.S. provisional applications, Ser. No. 60/490,111, filed Jul. 25, 2003, and Ser. No. 60/423,903, filed Nov. 5, 2002; and U.S. patent application Ser. No. 10/533,762 is a continuation-in-part of U.S. patent application Ser. No. 10/528,269, filed Mar. 17, 2005, now U.S. Pat. No. 7,274,501, which is a 371 application of PCT Application No. PCT/US2003/029776, filed Sep. 19, 2003, which claims priority of U.S. provisional applications, Ser. No. 60/489,816, filed Jul. 24, 2003; Ser. No. 60/424,116, filed Nov. 5, 2002; and Ser. No. 60/412,275, filed Sep. 20, 2002, which are all hereby incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to an electro-optic reflective element assembly for an electro-optic mirror assembly, such as an electrochromic interior or exterior rearview mirror assembly for a vehicle, and, more particularly, to an electro-optic rearview mirror assembly which includes an electro-optic reflective element assembly with a reduced bezel.

BACKGROUND OF THE INVENTION

Variable reflectivity mirror assemblies, such as electro-optic mirror assemblies, such as electrochromic mirror assemblies, are known and are widely implemented in vehicles. The reflective element assembly of such a mirror assembly often includes two substrates or glass elements with an electrochromic medium sandwiched therebetween. The back or outer surface of the second substrate (commonly referred to as the fourth surface of the reflective element assembly) may include a silvered coating to provide reflectance of an image. Each substrate is coated with at least one conductive or semi-conductive layer, which conduct electricity to the electrochromic medium from an electrical connector clipped or otherwise fastened or secured at least partially along an edge of the substrate and layer. An example of a known electrochromic reflective element assembly is shown in FIGS. 1 and 2. The reflective element includes an electrochromic (EC) medium layer 1 sandwiched between conductive layers 2 and a seal 7 at a front glass substrate 3 and a rear glass substrate 4 (and may include other conductive or semi-conductive layers). The substrates are offset so that an upper edge of one substrate and its conductive coating extends above the upper edge of the other substrate, while the lower edge of the other substrate and its conductive coating extends below the lower edge of the other substrate. This offset allows for electrical connection of electrical connectors or busbars 5 to the conductive coatings of each substrate, as shown in FIG. 2. The busbars or electrical connectors or clips extend substantially along the entire upper or lower edge of the respective substrate and coating. However, in order to manufacture the mirror element to obtain the desired offset, one or more offset or stepped spacers or pins 6 (shown in phantom in FIG. 2) must be placed along one of the upper and lower edges of the substrates to properly space the substrates from one another and to provide the offset along the edges when the substrates are placed in an assembly fixture.

As shown in FIG. 3, another conventional offset mirror element includes a coating on one of the substrates which provides a tab out portion 7 for connection of an electrical clip thereto. The substrates are offset in a similar manner as shown in the embodiment of FIGS. 1 and 2 to provide clearance at the tab out portion for the electrical connection. Such an embodiment also requires a stepped spacer or pin to provide the appropriate spacing between the substrates and to set the offset between the edges at the desired or appropriate amount.

Typically, it is desirable to minimize the size of the bezel or overlap of the casing/bezel (or even to eliminate the bezel) which extends around the reflective element of the mirror assembly. The bezel is typically required to extend over the front or first surface of the electrochromic cell or reflective element assembly to cover or hide or conceal, for example, the seal around the electrochromic medium of the electrochromic cell (that typically spaces the front substrate from the rear substrate, such as described in U.S. Pat. No. 6,002,511, which is hereby incorporated herein by reference), in order to conceal or hide the seal (and/or the electrical spring conductors, busbar conductors, clips, connectors and/or the like) which may otherwise be visible, particularly when the electrochromic medium is darkened. An exemplary and effective means for hiding the seal and, thus, minimizing the size of the bezel is disclosed in U.S. Pat. No. 5,066,112, which is hereby incorporated herein by reference. Also, and such as described in U.S. Pat. No. 6,449,082, which is hereby incorporated herein by reference, there is typically an offset to allow the clip or connector to connect to the cell or substrate that may influence the size of the overlap or bezel.

In cells or reflective element assemblies that may provide a small bezel or no bezel, it is often difficult to make electrical contact to the semi-conductive and/or conductive layers of the substrates with a restricted overhang between the substrates. A variety of methods have been used to provide electrical power to the semi-conductive and/or conductive layers of electrochromic cells, such as described in U.S. Pat. Nos. 5,066,112; 6,356,376; and 6,512,264, which are hereby incorporated herein by reference.

Therefore, there is a need in the art for an electrochromic mirror element which overcomes the above disadvantages and shortcomings of the prior art.

SUMMARY OF THE INVENTION

The present invention provides an electro-optic or electrochromic interior or exterior rearview mirror assembly which includes an electro-optic or electrochromic cell or reflective element assembly having a pair of substrates and an electro-optic or electrochromic medium disposed between the substrates. The reflective element assembly may include electrical connectors for providing electrical current to the conductive and/or semi-conductive layers or coatings at the surfaces of the substrates opposing the electro-optic medium. The electrical connectors may connect to the substrates at or behind an overhang region of the front substrate such that the connectors are substantially not viewable through the front substrate. The electrical connectors may be electrically isolated from one another and may connect to one of the substrates and may provide electrical current to the respective substrates. One edge or side of each of the substrates of the reflective element assembly may be in flush alignment, while allowing for electrical connection to one of the substrates along the generally flush edges.

According to an aspect of the present invention, a reflective element assembly for a mirror system of a vehicle includes front and rear substrates with an electro-optic medium sandwiched therebetween, a non-conductive seal disposed around a perimeter of the electro-optic medium and between the front and rear substrates, and first and second electrical connectors. The rear substrate has a smaller dimension across a dimension of the rear substrate than a corresponding dimension across the front substrate such that the front substrate defines a first overhang region at a first edge of the front substrate that extends beyond a corresponding first edge of the rear substrate. The front substrate has a first surface and a second surface opposite the first surface. The second surface faces the electro-optic medium, The front substrate has at least one first conductive layer disposed on the second surface. The rear substrate has a third surface and a fourth surface opposite the third surface. The third surface faces the electro-optic medium. The rear substrate has at least one second conductive layer disposed on the third surface. The second conductive layer includes a tab portion that extends at least to a second edge of the rear substrate. The rear substrate includes a non-conductive raceway proximate the second edge and devoid of the second conductive layer except at the tab portion. The non-conductive seal encompasses at least a portion of the second conductive layer and at least a portion of the raceway. The first electrical connector is in electrical connection with the first conductive layer and the second electrical connector is in electrical connection with the tab portion of the second conductive layer. The first electrical connector connects to the first conductive layer at the first overhang region so as to be behind the front substrate and substantially not viewable through the first surface of the front substrate.

The front substrate may include a hiding or concealing layer at the perimeter portions to substantially hide the connectors and seal from view by the driver of the vehicle.

According to another aspect of the present invention, a reflective element assembly for a mirror system for a vehicle includes front and rear substrates with an electro-optic medium sandwiched therebetween, a non-conductive seal disposed around a perimeter of the electro-optic medium and between the front and rear substrates, and first and second electrical connectors. The rear substrate has a smaller dimension across a dimension of the rear substrate than a corresponding dimension across the front substrate such that the front substrate defines a first overhang region at a first edge of the front substrate that extends beyond a corresponding first edge of the rear substrate. The front substrate has a first surface and a second surface opposite the first surface. The second surface faces the electro-optic medium. The front substrate has at least one first conductive layer disposed on the second surface. The rear substrate has a third surface and a fourth surface opposite the third surface. The third surface faces the electro-optic medium. The third surface of the rear substrate has a non-conductive portion proximate the first edge and devoid of the second conductive layer. The non-conductive seal encompasses at least a portion of the non-conductive portion of the rear substrate. The first electrical connector is in electrical connection with the first conductive layer and the second electrical connector is in electrical connection with the second conductive layer. The first electrical connector extends from the fourth surface of the second substrate and over at least a portion of the first edge of the second substrate and toward the first overhang region of the front substrate. The first electrical connector connects to the first conductive surface at the first overhang region so as to be behind the front substrate and substantially not viewable through the first surface of the front substrate. The non-conductive seal and the non-conductive portion substantially electrically isolate the first electrical connector from the second conductive layer.

According to another aspect of the present invention, an electro-optic or electrochromic mirror element includes a pair of substrates and an electro-optic or electrochromic medium sandwiched therebetween. Each of the pair of substrates includes at least one conductive or semi-conductive layer disposed thereon. The pair of substrates are positioned relative to one another such that the upper and/or lower edges of the substrates are substantially flush or aligned with one another. One of the substrates includes a relief area along the aligned edge to provide clearance for electrical connection to the conductive layer or layers of the other substrate along the aligned edge.

According to another aspect of the present invention, an electro-optic or electrochromic mirror assembly for a vehicle comprises an electro-optic or electrochromic reflective element assembly comprising a first substrate having first and second surfaces and a second substrate having third and fourth surfaces. The first and second substrates are arranged so that the second surface opposes the third surface with an electro-optic or electrochromic medium disposed therebetween. The first substrate has at least one at least partially conductive coating or layer on the second surface and the second substrate has at least one at least partially conductive coating or layer on the third surface. The first and second substrates are positioned relative to one another such that at least a portion of a first edge of the first substrate is generally flush or aligned with a corresponding edge of the second substrate. The first edge of the first substrate has a relief area formed therealong, wherein the relief area provides clearance for electrical connection to the corresponding edge of the second substrate.

In one form, the conductive coating of the second substrate includes a tab out portion at the corresponding edge. The relief area of the first substrate provides clearance for electrical connection to the tab out portion of the at least one conductive coating or layer. The first substrate may be the front substrate and the second substrate may be the rear substrate, with the aligned or generally flush edges being along the upper edges of the substrates.

Therefore, the present invention provides an electro-optic or electrochromic cell or mirror reflective element assembly that provides an overhang region at at least one edge of the front substrate for electrical connection to the conductive layer at the rear surface of the substrate, such that the electrical connection is not viewable through the front surface of the front substrate. The present invention thus may provide a reflective element assembly that is suitable for use in a bezelless mirror assembly, where the front surface of the reflective element is substantially entirely viewable by a driver of the vehicle. Optionally, a reflective element assembly of the present invention may provide a flush alignment of an upper and/or lower edge of a pair of substrates, while providing clearance for electrical connection to the upper and/or lower edges of one of the substrates and the respective conductive coating. The present invention thus provides enhanced assembly processes for the mirror element, since the substrates may be aligned with one another within an assembly fixture and do not require stepped pins or spacers positioned along one edge to provide sufficient offset or staggering between the substrates to provide clearance for electrical connection to one of the substrates along the aligned or flush edge thereof.

These and other objects, advantages, purposes, and features of the present invention will become apparent from the study of the following description in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a conventional electrochromic mirror element, showing a typical offset orientation of the two substrates;

FIG. 2 is a sectional view of a conventional electrochromic mirror element, showing a conventional spacer for use in manufacturing of the conventional mirror element;

FIG. 3 is a plan view of another conventional electrochromic mirror element similar to FIG. 1, with a tab out portion for electrical connection with a conductive or semi-conductive layer on one of the substrates;

FIG. 4 is a plan view of an electro-optic reflective element assembly of the present invention;

FIG. 5 is a sectional view of the reflective element assembly taken along the line V-V in FIG. 4, showing the clearance provided for electrical connection to each substrate;

FIG. 6 is a sectional view of the reflective element assembly taken along the line VI-VI in FIG. 4, showing the flush alignment of the upper edge of the substrates;

FIG. 7 is a sectional view of a generally flush electro-optic reflective element assembly in accordance with the present invention, with electrically conducting pins providing the electrical connection to the appropriate semi-conductive layer of the substrates of the reflective element assembly;

FIG. 8 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 9 is a sectional view of another flush electro-optic reflective element assembly in accordance with the present invention, with an extruded wraparound connector for providing electrical contact to the semi-conductive layers of the substrates of the reflective element assembly;

FIG. 10 is a sectional view of another electro-optic reflective element assembly similar to the reflective element assembly of FIG. 9;

FIG. 11 is a plan view of a generally flush electro-optic reflective element assembly for an exterior rearview mirror assembly in accordance with the present invention, with the substrates cut in generally opposite wave patterns to facilitate electrical connection to the respective semi-conductive layers of the substrates;

FIG. 12 is an enlarged plan view of a portion of the reflective element assembly of FIG. 11, with an electrical connector connecting to the exposed portion or wave peaks of an edge of one of the substrates of the reflective element assembly;

FIG. 13 is a plan view of another one sided flush electro-optic reflective element assembly in accordance with the present invention;

FIG. 14 is a plan view of the rear substrate of the reflective element assembly of FIG. 13, with a semi-conductive layer or coating on the third surface of the rear substrate;

FIG. 15 is a plan view of the rear substrate of FIG. 14, with a seal applied or disposed around the perimeter surface or region of the rear substrate;

FIG. 16 is a perspective view of a front substrate and a rear substrate of an electro-optic reflective element assembly in accordance with the present invention;

FIG. 17 is a sectional view of an electro-optic reflective element assembly having the substrates of FIG. 16;

FIG. 18 is an enlarged sectional view of an edge portion of the rear substrate of the electro-optic reflective element assembly of FIG. 17, showing an electrical connector extending from the rear surface of the rear substrate;

FIGS. 19 and 19A are enlarged sectional views of an edge portion of the electro-optic reflective element assembly of FIG. 17, showing an electrical connector for providing electrical connection to the rear surface of the front substrate;

FIG. 20 is another enlarged sectional view of a front substrate having a border perimeter coating in accordance with the present invention;

FIG. 21 is a plan view of the rear surface of another electro-optic reflective element assembly in accordance with the present invention, with the electrical connections provided at the front substrate;

FIG. 22 is a plan view of the rear surface of another electro-optic reflective element assembly similar to FIG. 21, but with the electrical connections provided at opposite corners of the reflective element assembly;

FIG. 23 is an enlarged plan view of one of the corners of the reflective element assembly of FIG. 22;

FIG. 24 is a plan view of another electro-optic reflective element assembly similar to the reflective element assembly of FIG. 21;

FIG. 25A is a plan view of the third surface of a rear substrate for an exterior electro-optic reflective element assembly in accordance with the present invention;

FIG. 25B is a plan view of the second surface of a front substrate for the exterior electro-optic reflective element assembly;

FIG. 26 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention, with the electrical connections provided at the front substrate;

FIG. 27 is a plan view of the electro-optic reflective element assembly of FIG. 26;

FIG. 28 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 29 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 30 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 31 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 32 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 33A is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIGS. 33B and 33C are plan views of the reflective element assembly of FIG. 33A;

FIG. 34 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 35 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 36 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 37 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 38 is a sectional view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 39 is a plan view of another electro-optic reflective element assembly in accordance with the present invention;

FIG. 40 is a front elevation of a combined ground illumination/turn-signal indicator system in accordance with the present invention;

FIG. 41 is a top plan view of the ground illumination/turn-signal indicator system of FIG. 40, with a security light assembly;

FIG. 42 is a view looking forwardly in the direction of travel of the vehicle of a lighted exterior mirror system in accordance with the present invention;

FIG. 43 is a side elevation and partial sectional view of a lighted interior mirror system in accordance with the present invention;

FIGS. 44 and 45 are side elevation and partial sectional views of alternate embodiments of lighted interior mirror systems in accordance with the present invention;

FIG. 46 is a view looking forwardly in the direction of travel of the vehicle of an exterior mirror system having a turn signal in accordance with the present invention;

FIG. 47 is a top plan view of a portion of the mirror system of FIG. 46;

FIG. 48 is a schematic of an improved exterior mirror lighting configuration of the present invention;

FIG. 49 depicts a cross-sectional view of another electrochromic mirror construction according to the present invention, wherein, in this construction, a secondary weather barrier 1112 has been applied to the joint at which sealing means 1105 joins substrates 1102, 1103;

FIGS. 50A, 50B and 50C depict the orientation of the substrates in different constructions of the electrochromic mirrors and electrochromic devices of the present invention, with FIG. 50A depicting a perpendicular displacement of the first substrate and the second substrate, FIG. 50B depicting a lateral displacement and a perpendicular displacement of the first substrate and the second substrate, and FIG. 50C depicting an arrangement of the first substrate and the second substrate, wherein the dimensions of the length and width of the first substrate are slightly greater than those of the second substrate, wherein, in this arrangement, the peripheral edge of the first substrate extends beyond the peripheral edge of the second substrate;

FIGS. 51A and 51B depict cross-sectional views of electrochromic devices, which illustrate different seal constructions that may be employed in accordance with the present invention; and

FIG. 52 depicts a perspective view of a multi-radius electrochromic mirror according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and the illustrative embodiments depicted therein, an electro-optic or electrochromic cell or mirror element assembly or reflective element assembly 10 for an interior rearview mirror assembly of a vehicle (not shown) includes first and second glass substrates 12, 14 and an electro-optic or electrochromic medium 16 disposed or sandwiched therebetween (FIGS. 4-6). Electrochromic medium 16 and at least one metallic and/or non-metallic conductive or semi-conductive layers 18, 20 are disposed on the inner surfaces 12 a, 14 a of substrates 12, 14 and between the electrochromic medium 16 and the respective substrate 12, 14. At least one of the edges or sides 12 b, 14 b of the substrates 12, 14 are generally aligned with or flush with one another (as seen in FIGS. 4 and 6) at least along a portion of the edges. The reflective element or mirror element of the present invention is equally suitable for interior or exterior rearview mirror assemblies for vehicles or for other mirror assemblies, without affecting the scope of the present invention.

Electrochromic mirror element assembly 10 comprises a first or front substantially transparent substrate 12 and a second or rear substantially transparent substrate 14 (which may be glass substrates or the like). The substrates are generally elongated along a longitudinal axis and define upper and lower edges and generally curved opposite side or end edges. Although shown and described as a reflective element assembly for an interior rearview mirror assembly or system, the reflective element assembly may be formed to be suitable for other mirror assemblies or systems, such as for an exterior rearview mirror assembly of a vehicle or the like.

The first substrate 12 of reflective element assembly 10 includes one or more electrically conductive or semi-conductive layers 18 (shown in FIGS. 5 and 6 and a single layer), such as a tin oxide or indium tin oxide (ITO) or any other transparent electrically semi-conductive layer or coating or the like (such as indium cerium oxide (ICO), indium tungsten oxide (IWO), indium oxide (IO) layers or the like, or a zinc oxide layer or coating, or a zinc oxide coating or the like doped with aluminum or other metallic materials, such as silver or gold or the like, or other oxides doped with a suitable metallic material or the like), deposited on an inward surface 12 a of first substrate 12 (i.e., the second surface 12 a of the mirror element assembly 10). As shown in FIGS. 5 and 6, coating 18 may extend substantially up to and along a lower edge 12 c of substrate 12 and may be electrically connected to a clip or busbar 22 extending along edge 12 c to provide electricity to coating or layer 18.

Rear or second substrate 14 includes at least one layer or coating of metallic conductive (such as a layer of silver, aluminum or an alloy of silver or an alloy of aluminum or other metal or metal alloy) or non-metallic semi-conductive material (such as an ITO layer or the like) 20 disposed on a forward or third surface 14 a of rear substrate 14 (shown in FIGS. 5 and 6 as three layers). The layers or coatings may be selected to provide sufficient reflectance of the mirror element and may provide a desired transmissivity if the mirror element includes a display at the fourth surface of the rear substrate, as discussed below. Optionally, the layers or coatings may define reflective and conductive layers or stacks of the types described in PCT application No. PCT/US03/29776, filed Sep. 19, 2003 by Donnelly Corporation et al. for MIRROR REFLECTIVE ELEMENT ASSEMBLY, published Apr. 1, 2004 as International Publication No. WO 2004/026633 A2, which is hereby incorporated herein by reference. Such a stack of layers comprises a metallic layer sandwiched between two semi-conductive layers (both of which preferably are the same material, but either of which can be different from the other). As shown in FIGS. 4 and 5, at least one layer 20 a is deposited directly on surface 14 a of substrate 14 and includes a tab out portion 21 extending toward and substantially up to edge 14 b at a generally central region 14 d thereof. An electrical clip 24 is connected to tab out portion 21 to provide electricity to the layer or layers 20 on substrate 14. The outer perimeter portion of rear substrate 14 is masked during the coating process such that the coatings or layers 20 do not cover surface 14 a at the outer perimeter portions except at tab out portion 21.

As can be seen in FIGS. 5 and 6, the first and second substrates 12, 14 are positioned in spaced-apart relationship with one another with an electro-optic or electrochromic medium 16 disposed between semi-conductive layer or layers 18 and semi-conductive layer or layers 20. A non-conductive seal 19 is positioned around the perimeter of the electrochromic medium 16 and around the perimeter of the semi-conductive layer 20 except at the tab out portion 21. The electrochromic medium 16 changes color or darkens in response to electricity or voltage applied to or through the semi-conductive layers 18 and 20 at either side of the electrochromic medium. The electrochromic medium 16 disposed between the front and rear substrates 12, 14 may be a solid polymer matrix electrochromic medium, such as is disclosed in U.S. Pat. No. 6,154,306, which is hereby incorporated by reference herein, or other suitable medium, such as a liquid or solid medium or thin film or the like, such as the types disclosed in U.S. patent application Ser. No. 09/793,002, filed Feb. 26, 2001 by Schofield et al. for VIDEO MIRROR SYSTEMS INCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268, and/or in U.S. Pat. Nos. 5,668,663 and 5,724,187, the entire disclosures of which are hereby incorporated by reference herein, without affecting the scope of the present invention. The electrochromic mirror element assembly may utilize the principles disclosed in commonly assigned U.S. Pat. No. 5,140,455; 5,151,816; 6,178,034; 6,154,306; 6,002,544; 5,567,360; 5,525,264; 5,610,756; 5,406,414; 5,253,109; 5,076,673; 5,073,012; 5,117,346; 5,724,187; 5,668,663; 5,910,854; 5,142,407 or 4,712,879, which are hereby incorporated herein by reference, or as disclosed in the following publications: N. R. Lynam, “Electrochromic Automotive Day/Night Mirrors”, SAE Technical Paper Series 870636 (1987); N. R. Lynam, “Smart Windows for Automobiles”, SAE Technical Paper Series 900419 (1990); N. R. Lynam and A. Agrawal, “Automotive Applications of Chromogenic Materials”, Large Area Chromogenics Materials and Devices for Transmittance Control, C. M. Lampert and C. G. Granquist, EDS., Optical Engineering Press, Wash. (1990), which are hereby incorporated by reference herein, and in U.S. patent application Ser. No. 09/793,002, filed Feb. 26, 2001 by Schofield et al. for VIDEO MIRROR SYSTEMS INCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268, which is hereby incorporated herein by reference. Mirror element assembly 10 may also include a seal (not shown) positioned around the outer portions of the layers 18, 20 and the electrochromic medium 16 to seal the layers and avoid corrosion of the metallic layer or layers.

During operation, a voltage may be applied to mirror element assembly 10 via busbars or clips or electrical connectors 22, 24 positioned around and engaging at least a portion of an outer edge of the semi-conductive layers 18, 20 (FIG. 5). The connectors may be connected to an appropriate power source or circuitry or control or the like, such as to a circuit board or the like at the rear of the electrochromic cell or reflective element assembly. Optionally, the circuitry may be applied to the rear surface of the rear substrate utilizing the principles described in U.S. provisional application Ser. No. 60/508,086, filed Oct. 2, 2003 by Schofield for MIRROR REFLECTIVE ELEMENT ASSEMBLY INCLUDING ELECTRONIC COMPONENT, which is hereby incorporated herein by reference.

The voltage applied by connectors 22, 24 is bled from semi-conductive layers 18, 20 to the electrochromic medium 16. Preferably, the layers provide for reduced resistance through the layers, which provides for faster, more uniform coloration of the electrochromic medium 16, since the electrons applied via busbars 24 at semi-conductive layer 20 a may bleed through the other semi-conductive layers 20 faster due to the enhanced conductivity in the conductive layers 20. Preferably, the layers 20 provide a sheet resistance of less than approximately 10 ohms per square, more preferably less than approximately 5 ohms per square, and most preferably less than approximately 2 ohms per square. Desirably, and particularly for larger area mirrors, the sheet resistance is less than approximately 1 ohm per square, such as in the range of approximately 0.1 to 0.7 ohms per square.

In order to provide enhanced performance of the electrochromic mirror element, each of the layers of the combination or stack of layers may have substantial conductivity and none of the layers significantly retard electron/electrical conductivity from one layer to the other throughout the stack, and, thus, do not impede the flow of electrons into the electrochromic (EC) medium. In this regard, it is desirable that one or more of the metallic layers comprises a metallic material (which is preferably a highly reflective material, such as silver or silver alloys or the like) having a specific resistivity of preferably less than approximately 5×10⁻⁵ ohm·cm, more preferably less than approximately 1×10⁻⁵ ohm·cm, and most preferably less than approximately 5×10⁻⁶ ohm·cm. Preferably, such a highly conductive metallic layer or layers is/are sandwiched between two non-metallic, partially conductive layers, preferably formed of a non-metallic material (such as a semi-conducting oxide, such as indium oxide, tungsten oxide, tin oxide, doped tin oxide or the like) having a specific resistivity of less than approximately 1×10⁻² ohm·cm, more preferably less than approximately 1×10⁻³ ohm·cm, and most preferably less than approximately 5×10⁻⁴ ohm·cm, such as disclosed in PCT application No. PCT/US03/29776, filed Sep. 19, 2003 by Donnelly Corporation et al. for MIRROR REFLECTIVE ELEMENT ASSEMBLY, published Apr. 1, 2004 as International Publication No. WO 2004/026633 A2, which is hereby incorporated herein by reference.

In the illustrated embodiment of FIGS. 4-6, semi-conductive layers 18, 20 a are deposited on the inward surfaces 12 a, 14 a of the respective substrates 12, 14. The semi-conductive layer 18, 20 a may be deposited on the glass or substrate 12, 14 via any suitable process. The particular thickness of the conductive layers may vary depending on the particular application of mirror element 10. Optionally, the semi-conductive layer 20 a on rear substrate 14 need not be transparent and may comprise a chromium layer or the like. However, the semi-conductive layer 20 a may comprise a generally transparent semi-conductive layer of coating, such as a tin oxide layer, an indium tin oxide (ITO) layer or the like, without affecting the scope of the present invention.

The transparent semi-conductive non-metallic layers on rear substrate 14 preferably comprise non-metallic transparent electrically conductive or semi-conductive materials, such as tin oxide, indium oxide, indium cerium oxide, indium tungsten oxide, nickel oxide, tungsten oxide, indium tin oxide, half-wave indium tin oxide, full wave indium tin oxide, doped tin oxides, such as antimony-doped tin oxide and fluorine-doped tin oxide, doped zinc oxides, such as antimony-doped zinc oxide and aluminum-doped zinc oxide and/or the like.

The metallic layer or layers on rear substrate 14 comprise a thin film or layer of metal, such as silver, aluminum, or alloys thereof, or the like, with a selected thickness to provide sufficient reflectivity and/or transmissivity, depending on the application of the mirror element and whether the mirror element includes a display, such as a display-on-demand or display-on-need type of display or the like, as discussed below. Preferably, the selected metallic material comprises silver, but may otherwise comprise a material selected from aluminum, silver alloys, aluminum alloys (such as 6061 or 1100 aluminum alloys or the like), manganese, chromium or rhodium, or any other metallic material which is sufficiently reflective and/or transmissive at a selected thickness, without affecting the scope of the present invention.

In a preferred embodiment, the semi-conductive layers 18, 20 a comprise indium tin oxide (ITO) and are deposited onto the surfaces 12 a, 14 a of the respective substrate 12, 14 via a hot deposition process, which may involve, for example, sputter deposition onto a heated substrate, with the heated substrate often being heated to a temperature of greater than about 200° C., sometimes greater than 300° C., as is known in the art. The combination of the semi-conductive layers 18, 20 a on the substrates 12, 14 defines a conductive substrate which may be used for various embodiments of a mirror element in accordance with the present invention.

The other semi-conductive layers and metallic layers of the layers 20 on rear substrate 14 (or other layers on front substrate 12) may be deposited onto semi-conductive layer 20 a via a cold deposition process, such as sputter coating or the like, onto an unheated substrate. Preferably, each of the layers 20 is deposited on second substrate 14 by a sputter deposition process. More particularly, the substrate 14 (including the semi-conductive layer 20 a already deposited thereon) may be positioned in one or more sputter deposition chambers with either planar or rotary magnetron targets, and with deposition of the layers being achieved by either reactive deposition of an oxide coating by sputtering from a metal target (or from a conductive, pressed oxide target) in an oxygen-rich atmosphere, or by DC sputtering from an oxide target, such as an indium oxide (IO), indium tungsten oxide (IWO), indium tin oxide (ITO) or indium cerium oxide (ICO) target or the like, such as described in PCT application No. PCT/US03/29776, filed Sep. 19, 2003 by Donnelly Corporation et al. for MIRROR REFLECTIVE ELEMENT ASSEMBLY, published Apr. 1, 2004 as International Publication No. WO 2004/026633 A2, which is hereby incorporated herein by reference. However, other processes for applying or depositing layers of conductive material or layers and metallic material or layers may be implemented, without affecting the scope of the present invention.

The rear substrate 14 is masked substantially around the outer region of surface 14 a during the deposition process, such that the semi-conductive and/or conductive layer or layers 20 is/are not deposited in the masked outer region. However, substrate 14 is not masked over the entire outer edge or region of substrate 14, in order to allow deposition of the layer or layers at a particular un-masked area, such that a tab-out portion or area 21 is formed in the layer or layers 20. The tab out area 21 facilitates electrical connection of connector 24 with the conductive layers 20.

As shown in FIG. 4, the upper edge 12 b of first or front substrate 12 is formed to have a flattened area or relief area 12 d along a generally central region thereof. The relief area 12 d may be formed by cutting the glass substrate along the edge 12 b. The relief area 12 d allows the upper edge 12 b along the outer or side regions 12 e to generally align with the outer or side regions 14 e of upper edge 14 b of rear substrate 14, while providing clearance at the center region 14 d of rear substrate 14 for the electrical connector or clip 24 to clip onto rear substrate 14 and coatings or layers 20. The relief area 12 d also forms a pocket that helps to contain the silicone material 23 (such as Shin-Etsu 3421 or the like) which protects the tab out portion 21. As can be seen in FIG. 4, front substrate 12 is slightly larger than rear substrate 14, such that when the outer or side regions 12 e, 14 e of upper edges 12 b, 14 b are aligned, the lower edge 12 c of front substrate 12 extends downward below the lower edge 14 c of rear substrate 14, to provide for connection of the busbar 22 along lower edge 12 c of front substrate 12.

Because the relief area 12 d along upper edge 12 b of front substrate 12 provides clearance for electrical connection to the other substrate 14, while also allowing for substantially flush alignment of the upper edges 12 b, 14 b of the substrates 12, 14, the present invention provides for enhanced assembly processes for assembling the mirror element and obviates the need for a stepped or offset spacer or pin. During assembly of the mirror element assembly 10, the substrates 12, 14 may be placed in a fixture with the outer regions 12 e, 14 e of the upper edges 12 b, 14 b of both substrates abutting a wall of the fixture. The wall of the fixture thus aligns the upper edges of the substrates, and a stepped pin or the like is not necessary to provide the appropriate offset or clearance for the electrical connections to each substrate. This eases the assembly process, since stepped pins do not have to be carefully placed at the appropriate places along the edges of the substrates to achieve the desired offset or clearance. Uniform pins may be placed between the substrates to provide the appropriate spacing or separation gap between the substrates during assembly.

Although shown and described as being generally aligned along the upper edges, the lower edges may alternately be aligned in a similar manner, without affecting the scope of the present invention. It is further envisioned that a similar relief area may be formed at both the upper edge of one substrate and the lower edge of the other substrate, such that both the upper and lower edges may be generally flush or aligned with one another, while providing clearance for electrical connection to both substrates and their respective conductive or semi-conductive layer or layers.

Optionally, the first (outermost) surface 12 f of front substrate 12 may be coated with an anti-wetting property, such as via a hydrophilic coating (or stack of coatings), such as is disclosed in U.S. Pat. Nos. 6,193,378; 5,854,708; 6,071,606 and 6,013,372, the entire disclosures of which are hereby incorporated by reference herein. Also, the first (outermost) surface 12 f of front substrate 12 may be optionally coated with an anti-wetting property, such as via a hydrophobic coating (or stack of coatings), such as is disclosed in U.S. Pat. No. 5,724,187, the entire disclosure of which is hereby incorporated by reference herein. Such a hydrophobic property on the first/outermost surface of the electrochromic mirror reflective elements (and on the first/outermost surface of a non-electrochromic mirror, non-electro-optical, conventional reflective elements) can be achieved by a variety of means such as by use of organic and inorganic coatings utilizing a silicone moiety (for example, a urethane incorporating silicone moieties) or by utilizing diamond-like carbon coatings. For example, long-term stable water-repellent and oil-repellent ultra-hydrophobic coatings, such as described in PCT International Publication Nos. WO0192179 and WO0162682, the entire disclosures of which are hereby incorporated by reference herein, can be disposed on the first (outermost) surface 12 f of front substrate 12. Such ultra-hydrophobic layers comprise a nano structured surface covered with a hydrophobic agent which is supplied by an underlying replenishment layer (such as is described in Classen et al., “Towards a True “Non-Clean” Property: Highly Durable Ultra-Hydrophobic Coating for Optical Applications”, ECC 2002 “Smart Coatings” Proceedings, 2002, 181-190, the entire disclosure of which is hereby incorporated by reference herein).

Referring now to FIG. 7, an electro-optic or electrochromic cell or reflective element assembly 110 for a rearview mirror assembly of a vehicle includes a first or front substrate 112 and a second or rear substrate 114 (which typically are made of glass, but may comprise a polymeric material or the like), with an electrochromic medium 116 disposed or sandwiched therebetween. The front substrate 112 includes a non-metallic, transparent semi-conductive layer 118 (such as indium tin oxide (ITO), doped tin oxide or the like, such as described in U.S. Pat. No. 6,002,511, which is hereby incorporated herein by reference) disposed on the rear or second surface 112 a, while the second or rear substrate 114 includes one or more metallic and/or non-metallic conductive or semi-conductive layers 120 (such as silver, silver alloy or other metal or metal alloy or the like) disposed on the front or inwardly facing or third surface 114 a of rear substrate 114. The electrochromic medium 116 is sandwiched between the semi-conductive or conductive layers 118, 120, and is contained therein via a seal 119 positioned around the perimeter of the electrochromic medium 116. The conductive or semi-conductive layers 118, 120, electrochromic medium 116 and seal 119 may be substantially similar to the layers, electrochromic medium and seal of mirror assembly 10, discussed above, such that a detailed description of these items need not be repeated herein.

As can be seen with reference to FIG. 7, reflective element assembly 110 may comprise a generally flush cell or reflective element assembly, with at least some of the perimeter edges 112 b, 114 b of the substrates 112, 114 being generally flush or aligned with one another. Electrical current may be applied to each of the semi-conductive or conductive layers 118, 120 via a respective pin or connecting member 122, 124 that contacts the respective semi-conductive or conductive layer and extends rearwardly out the back or fourth surface 114 c of the rear substrate 114 for electrical connection to an appropriate power source or circuitry or control or the like at the rear of the electrochromic cell or reflective element assembly.

The first pin or connecting member 122 may be attached to the first or front substrate 112, such as by counter sinking a head 122 a of pin 122 into the rear surface 112 a of front substrate 112, such that a body or shaft portion 122 b of pin 122 extends rearward therefrom. The pin 122 thus may contact (or may be contacted by) the semi-conductive layer or coating 118 on the second surface 112 a of front substrate 112 to make the electrical connection thereto. The pin may be countersunk in the rear surface 112 a of front substrate 112 prior to depositing or applying the semi-conductive layer 118 to the rear surface 112 a of the substrate 112. The substrate and pin assembly may then be placed in a vacuum deposition chamber/apparatus, such as a sputter deposition chamber or the like, to have the semi-conductive coating 118 deposited on both the surface 112 a of substrate 112 and on at least a portion of the pin 122 itself. Such an approach provides an effective electrical connection between the pin and the semi-conductive coating because the coating is also deposited on and contacts the electrical connector or pin.

As can be see in FIG. 7, the pin 122 may be countersunk within the rear surface 112 a of the front substrate 112 such that the head 122 a of the pin 122 is within the glass substrate and generally flush with the surface 112 of the substrate. A metallic layer or coating or busbar 126 may be applied around the perimeter region or surface of the substrate 112 to enhance the electrical connection between the pin and the outer perimeter portion of the semi-conductive layer 118. The metallic layer or coating 126 may comprise an opaque metallic layer to conceal or hide the seal 119 and electrical connectors and the like, so as to reduce the size of the bezel overhang which may otherwise be needed to provide the desired appearance of the perimeter edges of the mirror assembly. Optionally, the perimeter coating 126 may comprise a chromium oxide (often referred to as “black chrome”) or other metal or metal oxide or metal compound that is dark, such as black, and thus effectively hides or conceals the seal, connectors and the like, thereby obviating the need for a bezel around the perimeter of the reflective element assembly. The shaft portion 122 b of pin 122 may then extend through the seal and through a hole or aperture in the rear substrate 114. As can be seen in FIG. 7, the conductive coating 120 may not extend to the area where the pin 122 passes through rear substrate 114, such that a non-conductive glass surface or area or region 115 may be defined at the perimeter region of the surface 114 a of rear substrate 114. The non-conductive seal 119 may partially or substantially fill or encompass the non-conductive area 115, such that the non-conductive area 115 and non-conductive seal 119 electrically isolate or insulate the pin 122 from conductive layer 120 of rear substrate 114.

Similar to pin 122, pin 124 may be countersunk within the front or third surface 114 a of rear substrate 114, such that the head 124 a of pin 124 is generally flush with the third surface 114 a of the substrate. After the pin is countersunk within the rear substrate 114, the third surface 114 a of the substrate may be coated with the semi-conductive layer or layers, such that the semi-conductive layer 120 coats or contacts the head 124 a of pin 124 and makes electrical contact therewith. The shaft or body portion 124 b of pin 124 may extend through a hole or opening through substrate 114 and rearwardly from the substrate or cell for electrical connection to the appropriate power source or circuitry or control or the like at the rear of the reflective element assembly. As can be seen in FIG. 7, the front or third surface 114 a of rear substrate 114 may be masked during coating of the third surface in the area of the first pin 122, such that the conductive and/or semi-conductive coatings or layers 120 are not applied to or deposited on the surface 114 a in the region where shaft 122 b of pin 122 extends through substrate 114. This substantially precludes the possibility that pin 122 may come in contact with both semi-conductive layers 118, 120, which may short the electrochromic cell or reflective element assembly.

The pin connectors of the electrochromic cell or reflective element assembly of the present invention thus may facilitate a flush electrochromic cell or reflective element assembly, because no clips or busbars are required around the outside of the perimeter edges of the substrates to contact the semi-conductive and/or conductive layers of the substrates. Optionally, a perimeter coating, which may be substantially opaque and may be conductive or semi-conductive, may be applied along the perimeter regions or border of the semi-conductive layer of the first or front substrate, in order to mask or hide or conceal the seal and connectors and the like to enhance the aesthetic appearance of the electrochromic reflective element assembly and to minimize the size or overhang of the bezel of the mirror assembly. The perimeter coating or layer may be of the type disclosed in U.S. Pat. No. 5,066,112, which is hereby incorporated herein by reference, or may be any other type perimeter coating which may provide the desired result or appearance.

Referring now to FIG. 8, an electrochromic cell or reflective element assembly 210 comprises a flush or generally flush electrochromic reflective element assembly and includes a front substrate 212 having an semi-conductive coating or layer 218, and a rear substrate 214 having a conductive and/or semi-conductive coating 220, with an electrochromic medium 216 disposed or sandwiched between the conductive or semi-conductive layers 218, 220. An opaque or darkened or substantially opaquifying or hiding or concealing or light absorbing perimeter coating 228 may be applied around the perimeter region or surface of the semi-conductive coating 218 of front substrate 212 to mask or hide or conceal the seal 219 of the electrochromic reflective element assembly 210. Perimeter coating 228 may comprise a black or darkened or opaque coating (such as a substantially opaque or dark, such as black, coating or layer) and may be conductive (such as a metallic electric conductive layer or element) or a combined opaquifying or dark or black non-conductive layer closest to the substrate surface and a conductive layer on the opaquifying layer. The perimeter coating may provide a class A appearance (i.e. a surface readily viewable by a user of the vehicle and thus required to be aesthetically and functionally acceptable) and may comprise a black ink or the like that may provide a substantially uniform hiding and concealing layer which may be applied via an inkjet or screen print process or the like. If a non-conductive opaque layer (such as paint or ink or the like) is used on the substrate surface, it is desirable to apply a conductive layer (such as a conductive tape or coating or the like) overt the opaque layer. Optionally, the opaquifying layer may comprise a chrome oxide (sometimes referred to as “black chrome”), which may be substantially dark on the surface, and may be coated with a substantially pure metal or chrome (such as discussed below with respect to FIG. 20) to provide a conductive layer or raceway along the substrate. Preferably, the opaquifying conductive coating or layer comprises a silver and aluminum alloy, but may comprise other dark colored (preferably black) conductive inks and/or adhesives based on silver and/or silver alloys, such as an electrically conductive black epoxy, such as EPO-TEK H32E or EPO-TEK H32C, both of which are available from Epoxy Technology of Billerica, Mass. It is further envisioned that other colors (other than black) may be used for perimeter coatings an busbar hiding coatings to match the color of the mirror case or to match other desired colors or shades or the like.

A metallic or conducting connector layer 230 may be applied or disposed or positioned around the perimeter region of the perimeter coating 228 and may be folded or wrapped around to at least partially cover the perimeter edges 212 b of the substrate 212 so that an outer or edge portion 230 a may extend partially along the outer perimeter edge 212 b of the substrate and may be in contact with the semi-conductive layers on the surface 212 a of substrate 212. As shown in FIG. 8, an outer or edge portion 220 a of the conductive layers 220 of rear substrate 214 may also extend around or wrap around the outer perimeter edges 214 b of rear substrate 214.

The outer or edge portions 230 a of the metallic layer 230 and the outer or edge portions 220 a of the layers or layers 220 of rear substrate 214 thus may provide for electrical contact to the conductive layers of the substrate substantially around the perimeter of the electrochromic cell or reflective element assembly, without requiring overlap or offset between the cells, such as for known or conventional clips and busbars. The metallic layer 230 and conductive layers 220 thus may provide an electrical raceway around at least a portion of the reflective element to enhance electrical flow along the substrates to enhance the performance of the mirror cell. Optionally, the metallic layer 230 may be substantially hidden by the Class A type appearance of the opaque layer 228, such that the mirror cell or reflective element assembly may minimize the size of any bezel associated with the mirror assembly, while providing an aesthetically pleasing mirror reflective element and mirror assembly. The reflective element assembly of the present invention thus may provide a minimum bezel size or no bezel mirror cell or reflective element assembly.

With reference to FIG. 9, an electrochromic cell or reflective element assembly 210′ may be substantially similar to the electrochromic cell or reflective element assembly 210 shown in FIG. 8, and may include an outer wraparound connector 232, which may wrap around the perimeter of the reflective element assembly and provides for electrical contact between the metallic contacts or layers 230, 220 and the appropriate power source, circuitry or control or the like. In the illustrated embodiment, wraparound connector 232 comprises an extruded flexible member which includes a wire connector 234. The wire connector 234 extends along and through the wraparound connector 232 and connects to the metallic connector 230, and may connect at the other end to the appropriate power source, circuitry or control or the like. Wraparound connector 232 also includes a second wire connector 236 which extends through the wraparound connector 232 and may connect the conductive and/or semi-conductive layers 220 of the rear substrate 214 to the appropriate power supply, circuitry or control or the like. The extruded wraparound connector 232 may be formed with the wires positioned or inserted therein and extending or protruding partially from an appropriate location or locations along the wraparound connector so as to make a strong electrical connection or contact with the respective member or layer when the wraparound connector 232 is wrapped around and secured to the reflective element assembly 210′.

Similarly, as shown in FIG. 10, a wraparound connector 232′ may include a pair of electrical wires or metallic members 234′, 236′ extending therealong and partially protruding from an inner surface of the extruded wraparound connector 232′. One of the wires or members 234′ may partially protrude along the inner surface of the connector to contact the outer or edge portion 230 a of the metallic layer or connector 230 to make electrical connection thereto at least partially or substantially around the perimeter of the front substrate 212 of the electrochromic cell or reflective element assembly 210″. Likewise, the other wire or metallic member 236′ may protrude partially from the extruded wraparound connector 232′ to contact the outer or edge portion 220 a of the layer or layers 220 along the outer perimeter edge of the rear substrate 214 to make electrical connection thereto at least partially or substantially around the perimeter edge or edges of the rear substrate. One or more electrical wires or connectors may extend through the wrap around connector 232′ to contact the appropriate one of the wires or metallic members 234′, 236′, in order to provide electrical connection to between the wires 234′, 236′ and the appropriate power source, circuitry or control or the like at the rear of the reflective element assembly.

Although shown as having a single perimeter electrical connector or layer 230 along the second surface of the front substrate 212, the reflective element assemblies 210′, 210″ may optionally include a substantially opaque Class A layer between the connectors 230 and semi-conductive layer 218, such as described above with respect to the reflective element assembly 210 of FIG. 8. Optionally, the electrical connectors 230 may comprise an opaque conductive material and may provide a black or opaque appearance to hide or conceal the seal 219 and connectors of the reflective element assemblies, such as via utilizing principles disclosed in U.S. Pat. No. 5,066,112, which is hereby incorporated herein by reference.

Referring now to FIGS. 11 and 12, a flush electro-optic or electrochromic cell or reflective element assembly 310 for an exterior rearview mirror assembly of a vehicle comprises a front substrate 312 and a rear substrate 314. The reflective element assembly 310 also includes semi-conductive and/or conductive layers and electrochromic medium (not shown in FIGS. 11 and 12), such as described above or such as otherwise known in the art. As can be seen in FIGS. 11 and 12, both of the substrates 312, 314 are cut in a wave like pattern, such as a sine wave or the like, around the perimeter edges of the substrate, with the wave cut of the rear substrate 314 being about 180 degrees out of phase with the wave cut of the front substrate 312. When the substrates are generally aligned with one another, the waves are out of phase and provide alternating outward peaks for connection of an electrical connector at least substantially around the entire perimeter of the substrates and reflective element assembly.

The front and rear substrates of the reflective element assembly thus may have a full wraparound busbar connected at at least some of or most of or each of the outer points or peaks of the waves. As shown in FIG. 12, a clip or busbar 338 for providing electrical connection to the outward protrusions or peaks of the respective one of the substrates may include a plurality of clips or clip portions 338 a connected together by a connecting member 338 b. The spacing between the clips 338 a generally corresponds to the wavelength of the wave cut around the substrates. Although only one of the clips or busbars for the rear substrate 314 is shown in FIG. 12, the other clip or busbar for the front substrate 312 would be substantially similar to busbar 338, but with the clips aligning with the outward peaks or protrusions or wave portions of the wave cut around the front substrate. The clips may connect to or contact conductive layers or busbars or raceways (not shown in FIGS. 11 and 12) that are disposed along the perimeter edge of the substrate. The wave design or pattern may vary depending on the size and particular application of the mirror assembly, the conductivity of the semi-conductive and/or conductive coatings on the substrates, and/or the like. For example, the wave cut may change in amplitude and/or frequency depending on the particular application. The clips or busbars may also change to correspond with the changes in the wave profile.

The wave cut reflective element assembly or electrochromic cell may provide a faster coloring of the reflective element assembly or electrochromic cell and a more uniform transition from bleached to color because the electrical potential may be generally uniformly distributed at substantially all of the points along the perimeter of the reflective element assembly. The benefits associated with the wave cut design may be even more significant for larger mirror sizes. The wave cut design of the present invention may also facilitate implementation of a less expensive or lower conductivity substrate while having little or no affect on the performance of the reflective element assembly or electrochromic cell. The cell gap may thus also be made smaller to assist in reducing double imaging of the mirror assembly. Also, because the voltage may be distributed more uniformly across the electrochromic cell, the “banding effect” may be significantly less for the wave cut design. Because the electrochromic cell may be a generally flush electrochromic cell, multiple cells may be stacked on one another during the manufacturing process using less complicated and less costly fixtures and jigs, in order to reduce the manufacturing costs associated with the electrochromic cells. Also, by taking advantage of the overlapping areas of the substrates, the effective surface area of the perimeter seal around the electrochromic cell may be made larger than in conventional cells.

Referring now to FIGS. 13-15, a one sided flush electro-optic or electrochromic cell or reflective element assembly 410 includes a front substrate 412 and a rear substrate 414. The reflective element assembly 410 also includes an electro-optic or electrochromic medium and conductive and/or semi-conductive layers or coatings, which may be substantially similar to the elements of the reflective element assembly 10 of FIGS. 4-6, discussed above. As shown in FIG. 13, the front substrate 412 may comprise a substantially oval shaped substrate and may be downwardly offset with respect to the rear substrate 414, such that the lower edge 412 b of the front substrate 412 extends over and below the lower edge 414 b of the rear substrate 414 to facilitate electrical connection thereto. The rear substrate 414 is formed to have an upwardly extending portion or top hat portion 414 c along the middle region of the upper edge of the substrate 414, such that the upward extending portion 414 c is generally offset from the upper edge 412 c of front substrate 412, while the side portions or regions of the upper edges of the substrates are generally flush or aligned with one another.

The upward extending portion or top hat portion 414 c of rear substrate 414 thus may provide or facilitate electrical connection to the rear substrate, without requiring the substrates to be offset along the upper edges in the conventional manner. As shown in FIG. 14, the conductive coating 420 on the third surface of the rear substrate 414 may include a tab out portion 420 a for the electrical connector to connect thereto. The upward extending portion or top hat portion 414 c of the rear substrate 414 thus may provide for electrical connection to the conductive coatings on the rear substrate, while also providing for a substantially flush upper edge along a substantial portion of the upper edges of the reflective element assembly, such that offset pins and the like are not required during the manufacturing processes of the electrochromic cell or reflective element assembly 410. A seal 419 (FIG. 15) may be provided around the perimeter region or surface of the rear substrate 414 to encase or seal the electrochromic medium, such as discussed above.

Referring now to FIGS. 16-19, an electro-optic or electrochromic cell or reflective element assembly 510, such as for an interior or exterior rearview mirror assembly of a vehicle, includes a front substrate 512 and a rear substrate 514, with an electro-optic or electrochromic medium 516 (FIGS. 17 and 19) disposed or sandwiched therebetween. Front substrate 512 includes an opaquifying or darkening or hiding conductive coating or layer 519 (such as, for example, an opaque or black conductive epoxy or dark colored conductive frit or chrome oxide/metallic chrome bilayer or the like, or other materials such as described above with respect to layer 228) applied or deposited around the border or perimeter of the front substrate 512. The opaquifying layer 519 may at least partially wrap around the perimeter edges of the substrate so that an edge portion 519 c of opaquifying layer 519 extends at least partially along the perimeter edge 512 c of substrate 512. The front substrate 512 also includes a semi-conductive, transparent coating or layer 518 (such as an ITO layer or doped ITO layer or the like) applied to or deposited on the rear surface 512 a of front substrate 512 and overlapping the opaquifying or hiding conductive border layer or coating 519 (as can be seen with reference to FIG. 17). Alternately, the semi-conductive layer 518 may be applied to or deposited on the rear surface 512 a of front substrate 512 first, and then the opaquifying or black conductive layer may be applied to or deposited on the perimeter region of the semi-conductive layer 518. The conductive layer 519 provides an electrical raceway (due to the lower resistance provided by the conductive layer 519 versus the semi-conductive or ITO layer 518) around the perimeter of and in contact with the semi-conductive layer 518 to provide quick electrical flow around the perimeter of the semi-conductive layer to quickly energize the layer and get substantially uniform and even and rapid coloring or darkening of the reflective element assembly when electrical connection is made at the conductive layer 519, such as via an electrical connector 522 (FIG. 19).

The rear substrate 514 includes a metallic or conductive layer or coating 520, preferably a highly reflective metallic layer or coating (such as, for example, chromium, chromium/rhodium, silver, aluminum, silver alloy, aluminum alloy, ITO/silver/ITO stack, ITO/aluminum/ITO stack (such as ITO-silver-ITO stacks, display on demand stacks or infrared transmitting stacks of the types disclosed in PCT application No. PCT/US03/29776, filed Sep. 19, 2003 by Donnelly Corporation et al. for MIRROR REFLECTIVE ELEMENT ASSEMBLY, published Apr. 1, 2004 as International Publication No. WO 2004/026633 A2, which is hereby incorporated herein by reference) or the like) applied to or deposited on and substantially over the third surface 514 a of rear substrate 514. The outer perimeter edge area or border region 514 b of the third surface 514 a of the rear substrate 514 may be masked while the metallic reflector 520 is applied, such that the border region 514 b of the front surface 514 a of substrate 514 provides a non-conductive surface or path or raceway 514 e (such as a glass surface or the like) at least partially around the metallic reflector 520 and proximate to the edge 514 d of substrate 514.

As shown in FIG. 16, rear substrate 514 may also include a conductive coating or layer 521 (such as, for example, a conductive epoxy layer or a conductive silver frit layer or the like) applied to or deposited on or positioned at and partially along a perimeter edge 514 d of the substrate 514 (optionally, a third surface portion 521 a of the conductive layer 521 may extend partially along the border region 514 b of the third surface 514 a, or the conductive layer 521 may have an edge portion 521 c that may partially wrap around and onto and over the edge 514 d of substrate 514, or the conductive layer 521 may further include a rear portion 521 b (FIG. 18) that may extend or wrap further around to the rear or fourth surface 514 c of substrate 514). A tab out portion 520 a of conductive layer 520 may extend over the border region 514 b or raceway 514 e and may overlap the conductive coating 521 to provide an electrical contact point or region or area for the rear substrate 514, as discussed below. The non-conductive raceway 514 e thus is substantially devoid of the conductive layer 520 except at the tab portion. Optionally, the tab out portion 520 a may wrap at least partially around the edge dimension 514 d of the substrate 514 (such as shown in FIG. 16, where the tab out portion 520 a extends along an outer perimeter or border region 514 b of third surface 514 a of substrate 514 and may further extend at least partially along and over the perimeter edge 514 d of substrate 514 and over edge portion 521 c of conductive coating 521).

As shown in FIG. 17, the front substrate has a height dimension that is greater than a corresponding height dimension of the rear substrate, such that the upper perimeter region or edge portion 512 f and lower perimeter region or edge portion 512 g of front substrate 512 extend beyond the corresponding perimeter regions or edge portions 514 f, 514 g of rear substrate 514 and define upper and lower overhang regions 512 h, 512 i. The connector or connectors may connect to the conductive layer at the rear surface of the front substrate at the overhang region or regions 512 h, 512 i and thus may not interfere or overlap the perimeter edge of the front substrate. The overhang regions of the front substrate relative to the rear substrate thus may allow for the electrical connectors to connect to the respective conductive layers substantially or entirely within the viewable profile of the front substrate by extending along the respective perimeter edges of the rear substrate, such that the connectors do not overlap the perimeter regions of the front substrate and, thus, are not viewable at the front surface of the front substrate. The front substrate may include a hiding layer or concealing layer at the perimeter regions or overhang regions, such as at the rear surface of the front substrate, to substantially hide or conceal the connectors and the seal of the reflective element assembly. The reflective element assembly thus may be suitable for a bezelless or minimal bezel mirror assembly.

Although shown and described herein as having upper and lower overhang regions, the reflective element assembly of the present invention may have only one overhang region, such as for the electrical connection to the conductive layer on the rear surface of the front substrate, or may have one or more overhang regions elsewhere along the perimeter of the reflective element assembly, such as along one or both sides of the reflective element assembly or the like, without affecting the scope of the present invention. The overhang region or regions may be selected at the upper or lower edges or at one or both side edges of the reflective element assembly depending on the particular application of the reflective element assembly. For example, for an interior rearview mirror assembly, where the longitudinal axis of the reflective element assembly typically extends lengthwise along the reflective element assembly (such as generally horizontally when the reflective element assembly is installed in a vehicle), the overhang region or regions may be at the upper and/or lower edges of the reflective element assembly. Similarly, for an exterior mirror assembly of, for example, a truck or the like, where the longitudinal axis of the reflective element assembly may extend generally vertically when the reflective element assembly is installed at the truck or vehicle (in other words, where the width of the reflective element assembly is less than the height of the reflective element assembly), the overhang regions may be at the side edges of the reflective element assembly. The overhang regions may thus extend along the width dimension of the reflective element assembly. However, the overhang regions may be elsewhere along or around the edges of the reflective element assembly, without affecting the scope of the present invention.

As can also be seen with reference to FIG. 17, reflective element assembly 510 may provide an electrically conductive opaque or hiding or concealing layer 519 at least substantially around the perimeter edges of the front substrate, with the transparent semi-conductive layer 518 overlapping the opaque conducting layer 519 in the area at which the seal 517 is positioned around the electrochromic medium 516. The opaque conducting layer 519 thus provides a contacting region around the perimeter of the substrate for contacting the transparent semi-conductive layers or coatings 518. The seal 517 is positioned along the opaque conductive layer 519 and is thus masked or hidden by the opaque conductive layer to enhance the appearance of the reflective element assembly, particularly when the electro-optic or electrochromic medium is darkened or colored. The opaque conductive layer may thus allow for a smaller or no bezel overhang around the perimeter of the reflective element assembly. As can be seen in FIGS. 17 and 19, the seal 517 may be positioned around the masked or border region 514 b of the rear substrate 514. The non-conductive perimeter seal 517 at least partially fills or covers or encompasses the non-conductive glass surface or masked region 514 e to electrically isolate or insulate the conductive coating 520 from the conductive adhesive 526, such that the conductive coating 520 of rear substrate 514 is electrically isolated from connector 522 that connects to the conductive surface 518 of front substrate 512.

As shown in FIGS. 18 and 19, the front substrate 512 and rear substrate 514 may include electrical connectors or terminals 522 and 524, respectively, for providing electrical connection to the conductive or semi-conductive layers 518, 520. Particularly, and as shown in FIG. 18, rear substrate 514 may include an electrical connection terminal or connector 524 at its rear or fourth surface 514 c for providing electrical connection between the conductive metallic layer 520 and the appropriate electrical source, circuitry or control or the like at the rear of the reflective element assembly. The electrical connection terminal 524 may be soldered or adhered or attached (such as via electrically conductive adhesive or the like, such as a conductive coating or layer or the like) to, or may be mechanically contacting at (such as via a spring-action contact or the like) a rear portion 521 b of the conductive coating or layer 521 along the fourth or rear surface 514 c of rear substrate 514. The conductive layer 521 thus provides electrical connection between the terminal 524 at the rear or fourth surface 514 c of rear substrate 514 and the conductive layer 520 at the front or third surface 514 a of rear substrate 514.

As discussed above, the electrically conductive layer 521 may provide electrical connection to the metallic reflector 520 via the tab-out portion 520 a of the metallic reflector, which may be overcoated or applied to the front portion 521 a of the electrically conductive layer 521 along the front or third surface 514 a of the rear substrate 514. A potting material 526 (such as, for example, a silicone or urethane elastomer, preferably a conductive semi-elastomeric material or the like) may be applied or positioned over the rear surface (and may be applied partially or entirely around the outer perimeter edge of the substrate) to seal the connection of the connector terminal 524 and the conductive layer 521. The electrical connection terminal 524 may extend rearward from the reflective element assembly 510 and may protrude from the potting material 526 for electrical connection to a connector associated with the appropriate electrical power, circuitry or control or the like.

As shown in FIG. 19, the front substrate 512 of reflective element assembly 510 may include one or more electrical connection terminals 522 at or along its rear or second surface 512 a. The electrical connection terminal 522 may comprise a stick or ribbon or pin connector for providing electrical connection to the semi-conductive transparent layer 518 at the second surface 512 a of front substrate 512 and generally at or along the lower overhang region 512 i. The electrical connector or terminal 522 may be positioned entirely within a perimeter profile (as viewed from the front of the reflective element assembly) of the front substrate and generally rearward of the overhang region, so that the electrical connector or terminal is substantially not viewable through the front surface of the front substrate. The electrical connection terminal 522 may be soldered or adhesively attached, such as via an electrically conductive epoxy or the like, to the semi-conductive layer 518, or may be mechanically attached to or contacting the semi-conductive layer 518, such as via a spring-action contact or the like, and may extend or protrude rearward from the front substrate (and may extend rearward of the rear substrate as shown in FIG. 19) for electrical connection to the appropriate electrical power, circuitry or control or the like at the rear of the reflective element assembly.

As discussed above, the semi-conductive layer 518 may be applied to or deposited on the second surface 512 a of substrate 512 and on or over a perimeter black out or opaquifying layer 519. Optionally, as also discussed above, the perimeter layer 519 may be conductive. Optionally, as shown in FIG. 19, the perimeter opaquifying layer 519 may be non-conducting and applied to or deposited on the outer perimeter region 512 g of the rear surface 512 a of front substrate 512, and an electrical conducting perimeter busbar layer 519 a (such as a metallic or high electrical conducting layer) may be applied to the opaquifying layer 519 and may overlap or fold over to cover a portion of the side edge 512 c of substrate 512, such that the metallic or high electrical conducting busbar layer 519 a may provide the electrical connection to the semi-conductive layer 518, while the opaquifying layer 519 may function to substantially hide or conceal the metallic busbar layer 519 a and seal 517 of the reflective element assembly, such that the layers and seals and connectors are not viewable by a driver or occupant of the vehicle when viewing the reflective element assembly of the mirror assembly of the vehicle.

The potting material 526 may extend partially around the perimeter edge of the front substrate and substantially surround and seal the electrical connector 522 at the rear surface of the front substrate. Preferably, the material 526 surrounding the connector 522 may comprise a conductive material, such as a conductive epoxy, such as a conductive epoxy commercially available from DuPont, a conductive paste, a conductive tape, such as a copper tape with conductive adhesive, a conductive frit or the like, to provide an enhanced connection of the pin or connector 522 to the conductive layer or raceway and the semi-conductive or ITO layer or the like on the front substrate. As shown in FIG. 19, the connector 522 may contact the semi-conductive layer 518 at the conductive busbar layer 519 a, and the conductive material 526 may substantially surround the connector 522 to enhance the electrical connection between the connector and the semi-conductive layer 518 and/or the conductive busbar layer 519 a. Optionally, and with reference to FIG. 19A, the connector 522′ may be spaced from the semi-conductive layer 518 and conductive busbar layer 519 a and substantially surrounded by the conductive material 526, such that the conductive material 526 connects the connector 522 along the semi-conductive layer 518 and busbar layer 519 a. Because a substantial amount of conductive material 526 may be packed in or disposed around the connectors and along the semi-conductive layer and busbar layer to substantially fill the overlap region or area, the conductive material may provide enhanced electrical flow and electrical contact between the connector and the busbar layer, thereby improving the performance of the reflective element assembly. Therefore, the conductive material may provide a substantial raceway effect along the semi-conductive layer and busbar layer even if the conductive material is a weak conductor.

The conductive material or epoxy may be injected or disposed into the area of the reflective element assembly outside and around the perimeter seal to substantially fill the area and to enhance the conductivity around the connector 522 and conductive coating 518 of front substrate 512. Optionally, the conductive material or epoxy may be applied to the overlap region at the “empty cell” stage of the manufacturing process, where the cell has not yet been filled with the electrochromic medium. The empty cell, with the seal and conductive epoxy disposed thereon, may then be fired or heated together to cure or harden both the seal and the conductive epoxy in a single process.

Therefore, the opaquifying layer and semi-conductive and conductive layers, and the electrical connectors of the reflective element assembly 510 provide a concealed or hidden seal and electrical connectors, such that the bezel size may be reduced or eliminated, while providing an aesthetically pleasing rearview mirror assembly and reflective element. The overhang region of the front substrate relative to the rear substrate may allow for multiple electrical connectors or multiple-point contact between the front electrical/perimeter busbar and the appropriate electrical power or circuitry or control or the like at the rear of the reflective element assembly or cell.

Optionally, and as shown in FIG. 20, the rear or second surface 512 a′ of a front substrate 512′ may include multiple hiding layers 519′ around the perimeter regions (such as lower perimeter region 512 g′ of FIG. 20) of the substrate to conceal or hide the seal 517 and connectors (not shown in FIG. 20) of the reflective element assembly. For example, the hiding layers 519′ may include a “black chrome” layer 519 a′ (such as a chromium oxide layer or the like) applied to or deposited on the rear surface 512 a′ of the substrate and along the perimeter regions and overhang regions, and a chromium metal layer 519 b′, which may be sputter deposited or otherwise applied to the layer or layers of chromium oxide 519 a′. Alternately, other metals or metal compounds may be deposited on the perimeter regions of front surface 512 a′ of front substrate 512′, and preferably may be applied in a manner that results in a substantially opaque layer (that may be substantially non-conductive) at the surface of the substrate and a substantially pure, highly conductive metallic layer over the opaque layer, such as discussed below.

The coatings or layers on the second surface 512 a′ of substrate 512′ may be applied to or deposited on the second surface in a manner to provide multiple and varying layers of chromium oxide or other metals or metal compounds or the like to enhance the performance of the layers. For example, the central region of the second surface 512 a′ may be masked while leaving the border or perimeter region 512 b′ unmasked during the application or deposition of the layers 519′. The chromium oxide layer or layers 519 a′ or the like may be reactively sputter deposited or evaporated in an oxygen atmosphere to deposit a dark, light absorbing chromium layer on the perimeter region 512 b′ of the second surface 512 a′ of the front substrate 512′. While the chromium oxide is being deposited or applied to the perimeter region 512 b′, the oxygen gas level in the vacuum chamber may be gradually reduced to approximately zero, thereby providing varying layers 519 a′ of chromium oxide on the perimeter region 512 b′. The chromium metal conductive layer 519 b′ may then be sputter deposited or coated onto the chromium oxide layer or layers 519 a′, such as in a zero oxygen atmosphere, to deposit a metal conducting perimeter coating at the perimeter region 512 b′ of the rear surface 512 a′ of front substrate 512′. The front substrate 512′ may be removed from the vacuum chamber and the mask over the central region may be removed. The transparent semi-conductive coating or layer 518 may then be sputter deposited or coated or otherwise applied to or deposited on or across the entire rear surface 512 a′ of front substrate 512′. Such a process and coatings provide a build up of “black chrome” (such as approximately 500 angstroms to approximately 2,000 angstroms thick) initially, followed by “metallic chrome” (such as approximately 500 angstroms to approximately 3,000 angstroms thick), thereby forming a border or perimeter electrically conductive busbar, but with the black chrome layer being substantially non-reflecting when viewed from the first surface side of the front substrate or reflective element assembly. Although described as comprising chrome oxide, other metals may be provided to form a metal compound (such as chrome oxide, nickel oxide, silver oxide or the like) at the substrate surface and a substantially pure metallic deposit (such as chromium, nickel, silver or the like) to provide a highly conductive raceway. The metal compound may be sandwiched between the substrate and the substantially pure metal, and provides a dark (such as black) layer at the substrate surface to at least substantially conceal or hide the seals and connectors and the like, while the substantially pure metal is at the semi-conductive layer or ITO layer or the like.

Optionally, and according to another aspect of the present invention, an electro-optic or electrochromic mirror assembly for a vehicle may comprise an electro-optic or electrochromic mirror element or reflective element assembly comprising a front or first substrate having first and second surfaces and a rear or second substrate having third and fourth surfaces. The first and second substrates are arranged so that the second surface opposes the third surface with an electro-optic or electrochromic medium disposed therebetween. The first substrate has at least one at least partially conductive or semi-conductive coating or layer on the second surface and may also have an opaquifying conductive border/perimeter coating/layer around the perimeter edges or regions of the substrate. The second substrate has at least one at least partially conductive coating or layer on the third surface. The first and second substrates are positioned relative to one another such that at least a portion of an edge of the first substrate is generally flush or aligned with a corresponding edge of the second substrate. The edge of the second substrate may have a relief area formed therealong relative to the edge of the first substrate, wherein the relief area provides clearance or access for electrical connection to the conductive border/perimeter coating/layer on the second surface of the corresponding edge of the first substrate. The electrical connections to the first substrate may provide or deliver electrical power to the semi-conductive coating on the second surface of the first substrate and to the conductive coating on the third surface of the second substrate, as discussed below.

The perimeter seal of the reflective element assembly may be formed such that the outer edge of the perimeter seal is generally flush with the edges of both the first and second substrates except in the relief area or areas formed along the edge of second substrate. The perimeter seal profile in the relief areas along the edge of the second substrate may be configured such that the outer edge of the perimeter seal is recessed from the outer edges of both the first and second substrates, such that a gap or spacing between the first and the second substrates is created outside of the seal. A conductive material or bridge may be disposed or applied at the gap or spacing to couple the conductive coating on the third surface of the second substrate with the appropriate electrical connector or contact at the border/perimeter conductive coating/layer on the second surface of the first substrate. In addition, in order to avoid shorting of the positive and negative electrical contacts, a small portion of the border/perimeter conductive coating/layer and the underneath transparent semi-conductive coating on the second surface of the first substrate may be removed (electrically isolated) in a pattern generally around the electrical contact for the second substrate at the spacing created in the relief area or areas formed along the edge or edges of the substrates. Electrical contact to the semi-conductive layer of the second surface of the first substrate may be made by affixing an electrical lead to the perimeter/border conductive coating/layer in the relief areas, while electrical contact to the third surface of the second substrate may be made by affixing an electrical lead to the perimeter/border conductive coating/layer of the first substrate in the electrically isolated portion of the relief area or areas. The electrical contact is then made to the third surface of the second substrate via the conductive material or bridge between the first and second substrates at the electrically isolated relief area or areas.

The electrical contacts to the transparent semi-conductive layer on the front substrate and the reflective conductive layer on the rear substrate may thus be made at one of the substrates, with a conductive bridge connecting one of the contacts at one substrate to the coating or layer on the other substrate. Such a configuration or arrangement may provide for a true flush, bezelless cell or reflective element assembly and may facilitate making both electrical contacts to the front substrate at specified areas or relief areas along the perimeter edges or regions of the substrates.

For example, and with reference to FIG. 21, an electro-optic or electrochromic reflective element assembly or cell 610 includes a front substrate 612 and a rear substrate 614 and may provide generally flush edges of the substrates substantially around the reflective element assembly. As shown in FIG. 21, the front substrate 612 may provide a top hat form or protrusion 612 c along the upper edge of the front substrate, and the rear substrate 614 may also provide a smaller top hat form or protrusion 614 c along its upper edge (such as discussed above with respect to the rear substrate 414 of FIGS. 13-15). The seal around the electrochromic medium is positioned along and between the outer edges of the substrates, except at the top hat forms. The top hat form 614 c of rear substrate 614 thus generally overlaps the top hat form 612 c of front substrate 612, with a gap or spacing defined between the top hat forms 612 c, 614 c and outward of the seal.

The second surface or rear surface of front substrate 612 is coated with a semi-conductive transparent coating or layer and a perimeter busbar layer 619 a and perimeter opaquifying or “black-out” layer 619 around its perimeter edges, such as, for example, coatings or layers similar to the busbar layer 519 a and opaquifying layer 519 of reflective element assembly 510, discussed above. As can be seen in FIG. 21, the top hat form 612 c of front substrate 612 provides for electrical contacts or connectors 622 (such as pins or clips or the like) at the perimeter busbar layer 619 a at either or both ends of the top hat form 612 c. A gap or deletion line 621 may be provided along a portion of the conductive layer on top hat form 612 c to electrically isolate a center portion or region 621 a of the top hat form 612 c from the ends of the top hat form where the positive electrical contacts are provided. An electrical contact or connector 624 (such as a pin or clip or the like) may be provided at the electrically isolated region 621 a.

Top hat form 614 c of rear substrate 614 may be coated with the conductive coating on the third surface of the substrate and/or may have a conductive coating or layer and tab-out edge of the conductive coating on the surface (such as, for example, a conductive coating or layer and tab-out portion of the types described above with respect to FIG. 16). The second or rear substrate 614 may include a perimeter, electrically conductive coating or layer around the perimeter edges and perimeter regions of the third surface of the rear substrate 614 (such as, for example, a perimeter electrically conductive coating of the type described above with respect to FIG. 18).

Reflective element assembly 610 further includes a conductive material or bridge 623, such as a conductive epoxy or the like, disposed at the electrically isolated region 621 a and spanning the gap between the top hat forms 612 c, 614 c of the front and rear substrates. The conductive bridge 623 provides for electrical connection between the electrically isolated region 621 a (and the electrical connector 624 connected thereto) of the top hat form 612 c of front substrate 612 and the conductive coating or layer or tab-out region of the top hat form 614 c of rear substrate 614.

Accordingly, electrical power may be applied to the semi-conductive coating or layer on the second surface of the front substrate via an electrical connector or contact (such as a pin or clip or the like) at the top hat form of the front substrate. Electrical power may also be applied to the conductive coating or layer on the third surface of the rear substrate via an electrical connector or contact (such as a pin or clip or the like) also positioned at the top hat form of the front substrate (and via the conductive bridge). The present invention thus provides a flush electro-optic or electrochromic cell or reflective element assembly with electrical contacts at only one of the substrates.

Optionally, and with reference to FIGS. 22 and 23, an electro-optic or electrochromic mirror cell or reflective element assembly 610′ may provide one or more relief regions 625 around the perimeter edges of the reflective element assembly, such as at generally opposite corners of the reflective element assembly 610′. The relief regions 625 may be defined by areas or regions of the rear substrate 614′ which may be cut back relative to the corresponding edge or edges of the front substrate 612′ to provide a relief area exposing the second surface of the front substrate 612′ when the reflective element assembly is viewed from the rear of the reflective element assembly. The front and rear substrates 612′, 614′ may otherwise be generally flush along their edges except at the relief regions 625.

The front substrate 612′ may include a transparent semi-conductive layer on its second or rear surface and may include a busbar layer 619 a′ (which may include a tab out portion 619 b′ over the relief region or regions 625) and/or a opaquifying or black-out layer around its perimeter edges and an electrical contact 622′ at each of the areas or regions exposed by the relief regions (such as discussed above). The electrical contact 622′ is electrically connected to the semi-conductive layer and busbar layer or tab out portion on the front substrate 612′. Each of the areas or regions of the second surface of the front substrate that are exposed by the relief regions also includes a deletion line 621′ that defines an electrically isolated area or region 621 a′. A second electrical contact 624′ is applied or connected to the electrically isolated region 621 a′ of each of the relief regions.

As can be seen in FIGS. 22 and 23, the seal 617′ around the electro-optic or electrochromic medium of the reflective element assembly may be configured or arranged to be between the front and rear substrates and generally along the perimeter edges of the front and rear substrates, except in the relief regions 625. At the relief regions 625, the seal may be positioned inward of the outer edges 614 c′ of the rear substrate 614′, which are inward of the outer edges 612 c′ of the front substrate 612′. A gap or spacing thus exists between the front and rear substrates outside of the seal 617′ and at each of the relief regions 625. The electrically isolated region 621 a′ is formed to generally correspond with the area of the substrates that have the gap or spacing therebetween. A conductive material or bridge 623′ is provided between the front and rear substrates at each of the relief regions to conductively span the gap between the electrically isolated area 621 a′ (and electrical connector 624′) of the front substrate 612′ and the conductive coating or layer or layers of the rear substrate 614′.

Optionally, and as shown in FIG. 24, the reflective element assembly 610″ may include a perimeter conductive coating or busbar coating 619 a″ around the perimeter of the front substrate 612′ and a seal 617″ around the perimeter of the substrates except at the relief region 625″ of the rear substrate 614″. In the illustrated embodiment of FIG. 24, the electro-optic or electrochromic reflective element assembly includes one relief region 625″ (defined by the cut off or reduced edge 614 c″ of rear substrate 614″), but could include two or more, such as at opposite corners of the reflective element assembly or the like, without affecting the scope of the present invention. The reflective element assembly 610″ is otherwise substantially similar to reflective element assembly 610′, discussed above, such that a detailed discussion of the reflective element assembly will not be repeated herein.

The electro-optic or electrochromic mirror cell or reflective element assembly 610′ thus may provide for electrical connections at two or more locations around the mirror cell or reflective element assembly, and may provide for the electrical connections at only the front substrate of the reflective element assembly. The reflective element assembly thus may provide a flush reflective element assembly or mirror cell that may be implemented in a bezelless mirror assembly, while providing enhanced performance or coloring or darkening of the reflective element assembly.

Optionally, and with reference to FIGS. 25A and 25B, an exterior rearview mirror cell or reflective element assembly for an exterior rearview mirror assembly of a vehicle includes a first or front substrate 712 (FIG. 25A) and a second or rear substrate 714 (FIG. 25B) and an electro-optic or electrochromic medium and seal 717 sandwiched therebetween, such as described above. As also described above, the front substrate 712 may have a transparent semi-conductive layer or coating 718 (such as ITO or the like) applied to the second or rear surface 712 a of the substrate, and may include an opaquifying conductive border/perimeter coating or layer 719 (such as, for example, a black conductive epoxy or dark colored conductive frit or black chrome/metallic chrome layer or the like) applied around the perimeter edges of the front substrate 712. As shown in FIG. 25A, the perimeter coating or layer 719 may be along the perimeter edges of the front substrate 712 except in an electrical connection area or region 725 of substrate 712, where the perimeter coating 719 is inward of the outer edges of substrate 712. The electrical connection region 725 is coated by the semi-conductive layer 718 and/or a conductive layer or the like. A deletion line 721, such as a non-conductive area in the region 725 where the busbar layer and semi-conductive layer is etched off or otherwise removed from or not applied to the surface of the substrate, is formed at the electrical connection area 725 to separate and define and electrically isolate a rear substrate electrical connection area 725 a or raceway portion of the semi-conductive layer from a front substrate electrical connection area 725 b or surface portion of the semi-conductive layer.

An electrical connection or contact 722 is connected to or applied to the front substrate electrical connection area 725 b to provide electrical power or connection to the semi-conductive layer 718 on the rear surface of the front substrate 712. Likewise, an electrical connection or contact 724 is connected to or applied to the electrically isolated rear substrate electrical connection area 725 a and is in electrical communication with the conductive layer of the third surface 714 a of rear substrate 714 via a conductive material or bridge 723, as discussed below.

With reference to FIG. 25B, rear substrate 714 includes a metallic reflector layer 720 (such as a layer or layers comprising, for example, chromium, chromium/rhodium, aluminum, silver, aluminum alloy, silver alloy, an ITO/silver/ITO stack, an ITO/aluminum/ITO stack or the like, such as ITO-silver-ITO stacks or layers, or display on demand stacks or layers or infrared transmitting stacks or layers of the types described in PCT application No. PCT/US03/29776, filed Sep. 19, 2003 by Donnelly Corporation et al. for MIRROR REFLECTIVE ELEMENT ASSEMBLY, published Apr. 1, 2004 as International Publication No. WO 2004/026633 A2, which is hereby incorporated herein by reference) on its front or third surface 714 a, and a perimeter black seal 717 generally around the perimeter edges of the substrate. As can be seen in FIG. 25B, an electrical connection area 727 may be defined at a region of the rear substrate 714, such as at a corner of the substrate, where the perimeter seal 717 is positioned inward of the outer edge of the substrate. The rear substrate 714 is formed to be substantially identical in shape to the front substrate 712, except at the electrical connection area 727, where the rear substrate may be cut back or reduced along a cut-away or cut back edge 714 c. The conductive bridge 723 is positioned at a portion of the electrical connection area 727 to provide electrical connection to the metallic reflective coating or layer 720 via electrical connector 724 at front substrate 712.

When the substrates 712, 714 are placed together to form the electro-optic or electrochromic mirror cell or reflective element assembly (with the electro-optic or electrochromic medium disposed or sandwiched therebetween), the electrical connection area 727 of rear substrate 714 generally aligns with a portion of the electrical connection area 725 of front substrate 712. The conductive bridge 723 bridges or spans the gap or spacing between the electrical connection areas 725 a and 727 to connect the electrical contact or connector 724 and electrical connection area 725 a to the metallic conductive reflective layer 720 of rear substrate 714.

The cut-away edge 714 c of rear substrate 714 provides for exposure of the electrical connectors or contacts 722, 724 along the outer edge 712 c of the electrical connection area 725 of front substrate 712. The electrical contacts for providing electrical power to the conductive or semi-conductive layers at both substrates are made at only one of the substrates. The other edges of the substrates 712, 714 are generally flush or aligned to form a flush reflective element assembly for an exterior rearview mirror assembly. The reflective element assembly may thus be implemented in a mirror assembly having a minimal bezel or a bezelless mirror assembly to enhance the appearance of the mirror assembly.

Referring now to FIGS. 26 and 27, an electro-optic or electrochromic mirror cell or reflective element assembly 810 includes a front substrate 812 and a rear substrate 814 and an electro-optic or electrochromic medium 816 sandwiched between the semi-conductive or conductive layers 818, 820 on the surfaces 812 a, 814 a of the substrates 812, 814, respectively. A dimension of the front substrate, such as a height dimension, is greater than that of the rear substrate, such that the upper and lower perimeter regions or edge portions 812 b, 812 c of front substrate 812 extend beyond the upper and lower perimeter regions or edge portions 814 f, 814 g of rear substrate 814 and define overhang regions 812 f, 812 g. As shown in FIG. 26, the conductive layer 820 of rear substrate 814 does not extend fully over third surface 814 a at the perimeter region 814 g of substrate 814. Third surface 814 a may be masked during the coating process, such that a non-conductive glass surface 814 e is provided generally along the perimeter region 814 g of surface 814 a.

Reflective element assembly 810 includes electrical connectors 824, 822 at a rear surface 814 b of rear substrate 814 and at least partially along the upper edge 814 c and lower edge 814 d of rear substrate 814, respectively. The connectors may be disposed partially at the rear surface 814 b of rear substrate 814 and may extend along and overlap the edges 814 c, 814 d of rear substrate 814. The electrical or metallic connectors 824, 822 are in electrical connection with the respective conductive layers 820, 818 and may be connected to an electrical power source or circuitry or the like to provide electrical power to the semi-conductive coatings 818, 820 to darken or color the electrochromic medium 816. The front substrate 812 includes a deletion line 821 along the upper portion 812 b of the substrate and along the semi-conductive coating or layer 818 on the rear surface 812 a of substrate 812. The deletion line 821 defines an electrically isolated area or region 821 a along a perimeter region of substrate 812, such as along the upper portion of the substrate 812.

As can be seen with reference to FIG. 27, the reflective element assembly 810 includes a non-conductive perimeter seal 817 around the electrochromic medium 816, as is known in the art. The seal 817 overlaps and at least partially or substantially fills or encompasses the deletion line 821 along one side of the reflective element assembly and at least partially or substantially fills or covers or encompasses the masked surface 814 e along the other side of the reflective element assembly. A conductive material or adhesive or bridge or the like 823 a is disposed or applied along the upper region of the front substrate and outside of the seal 817, while a conductive material or adhesive or bridge or the like 823 b is disposed or applied along the lower region of the front substrate and outside of the seal 817. Accordingly, when power is applied to connector 822, the connector provides or delivers power to or energizes the semi-conductive layer 818 on front substrate 812 via the conductive bridge 823 b (whereby the conductive bridge may function as an electrical raceway along the edge of the reflective element assembly). The non-conductive seal 817 and non-conductive surface 814 e of rear substrate 814 function to electrically isolate or insulate connector 822 and conductive bridge 823 b from conductive coating or layer 820 of rear substrate 814. When power is applied to connector 824, the connector provides or delivers power to the conductive layer 820 on rear substrate 814 via contact of the connector 824 along the edge of the conductive coating 820 and via the conductive bridge 823 a along the edge or perimeter region of the reflective element assembly. The conductive bridge 823 a and raceway portion 821 a may function as an electrical raceway along an edge portion or perimeter region of the conductive layer or coating 820 of rear substrate 814. The conductive bridge 823 a does not power the semi-conductive layer 818 on front substrate 812 because the conductive bridge 823 a is at the electrically isolated area 821 a along the upper portion or perimeter region of the front substrate.

Optionally, and as shown in FIG. 28, an electro-optic or electrochromic mirror cell or reflective element assembly 810′ may include metallic connectors 822′, 824′ that extend across the gap between the substrates 812, 814 and contact the semi-conductive layer 818 on the rear surface 812 a of the front substrate 812. The conductive bridge 823 functions to communicate the power from connector 824′ to the conductive layer 820 on the front surface 814 a of rear substrate 814. The deletion line 821 defines the electrically isolated area 821 a along the front substrate where the connector 824′ connects to or contacts the semi-conductive layer 818 of the front substrate 812 at the overhang region 812 f of front substrate 812. The connector 822′ contacts the surface portion of the semi-conductive layer 818 (which substantially covers the rear surface of the front substrate 812) along the other border or perimeter region or overhang region 812 g of the front substrate. The non-conductive glass surface 814 e and non-conductive perimeter seal 817 function to electrically isolate or insulate the connector 822′ from conductive coating 820 of rear substrate 814. The mirror cell or reflective element assembly 810′ is otherwise substantially similar to the reflective element assemblies discussed above, such that a detailed discussion of the reflective element assembly will not be repeated herein.

Optionally, and as shown in FIG. 29, a reflective element assembly 810″ is substantially similar to the reflective element assembly 810′, discussed above, but includes conductive pins or foil strips 822″, 824″. The foil strips 822″, 824″ are disposed between a heater pad or backing plate 811 and the semi-conductive layer 818 at the rear surface 812 a of the front substrate 812. The strips 822″, 824″ may include one or more pins or extensions 822 a″, 824 a″ extending rearwardly through the backing plate 811 for connection to an appropriate power source, control or circuitry or the like. The conductive bridge 823 functions to communicate the power from strip 824″ to the conductive layer 820 on the front surface 814 a of rear substrate 814. The deletion line 821 defines the electrically isolated area 821 a along the front substrate where the strip 824″ connects to or contacts the semi-conductive layer 818 of the front substrate 812. The strip 822″ contacts the surface portion of the semi-conductive layer 818 along the other border or perimeter region of the front substrate and may function as an electrical raceway along the border region of the semi-conductive layer 818. The mirror cell or reflective element assembly 810″ is otherwise substantially similar to the reflective element assemblies discussed above, such that a detailed discussion of the reflective element assembly will not be repeated herein.

Optionally, and with reference to FIG. 30, a reflective element assembly 810′″ includes metallic connectors or strips or foil 822′″, 824′″ that are inserted partially between the substrates 812, 814. The strip or foil 822′″ extends across the gap between the substrates 812, 814 and contacts the semi-conductive layer 818 on the rear surface 812 a of the front substrate 812 and generally at the overhang region 812 g. The strip or foil 824′″ contacts and connects to the conductive layer 820 on the front surface 814 a of rear substrate 814. The deletion line 821 defines the electrically isolated area or raceway portion 821 a along the front substrate where the strip or foil 824′″ is generally positioned to isolate that portion of the front substrate to avoid shorting of the cell or reflective element assembly due to any contacting of the strip or foil 824′″ to the surface portion of the semi-conductive layer 818 of the front substrate 812. The mirror cell or reflective element assembly 810′″ is otherwise substantially similar to the reflective element assemblies discussed above, such that a detailed discussion of the reflective element assembly will not be repeated herein. As can be seen in FIG. 31, the connectors or strips or foils 822′″, 824′″ may be insulated on their sides 822 a′″, 824 a′″ opposite to their electrically contacting side, such that the deletion line is not necessary.

Optionally, and with reference to FIG. 32, an electro-optic or electrochromic cell or reflective element assembly 910 includes a front substrate 912 and a rear substrate 914 with an electro-optic or electrochromic medium 916 sandwiched between a semi-conductive layer or coating (such as ITO or the like) 918 on the rear surface 912 a of the front substrate 912 and a conductive layer or coating 920 (such as silver, silver alloy, or the like) on the front surface 914 a of the rear substrate 914. A perimeter seal 917 is disposed around the electrochromic medium 916. As can be seen in FIG. 32, the conductive layer 920 is applied or coated or oversprayed at least partially onto the edges 914 b, 914 c of the rear substrate 914. The conductive layer 920 on the rear substrate 914 includes a deletion line 921 to define an electrically isolated area or raceway portion 921 a along a perimeter or border region or portion of the rear substrate 914. A conductive material or bridge 923 (such as a conductive epoxy, frit, paste or the like) is disposed along the perimeter or border region and between the electrically isolated area 921 a and the semi-conductive layer 918 of front substrate 912.

An electrical connector 922 is disposed at the rear substrate, such as partially along the rear surface 914 d of rear substrate 914, and overlaps at least a portion 920 a of the conductive layer 920 on the edge 914 b of rear substrate 914, thereby providing an electrical connection from the rear of the reflective element assembly 910 to the electrically isolated area 921 a of the conductive layer 920. The connector 922 thus provides an electrical connection to the semi-conductive layer 918 on the rear surface 912 a of the front substrate 912 via the conductive bridge 923 extending along and between the isolated area 921 a and the semi-conductive layer 918 at the perimeter or border regions of the front and rear substrates. The isolated area 921 a and the conductive bridge 923 provide an electrical raceway along a perimeter or border portion of the semi-conductive layer 918 to enhance the performance of the reflective element assembly 910.

A second electrical connector 924 is disposed partially along the rear surface 914 d of the rear substrate 914 and overlaps at least a portion 920 b of the conductive layer 920 at the edge 914 c of rear substrate 914, thereby providing an electrical connection from the rear of the reflective element assembly 910 to the conductive layer 920 along the front surface 914 a of rear substrate 914.

Referring now to FIGS. 33A-C, an electro-optic or electrochromic cell or reflective element assembly 1010 includes a front substrate 1012 and a rear substrate 1014 with an electro-optic or electrochromic medium 1016 sandwiched between a semi-conductive layer or coating (such as ITO or the like) 1018 on the rear surface 1012 a of the front substrate 1012 and a conductive layer or coating (such as silver, silver alloy or the like) 1020 on the front surface 1014 a of the rear substrate 1014. A perimeter seal 1017 is disposed around the electrochromic medium 1016. The semi-conductive layer 1018 on the front substrate 1012 includes a deletion line 1019 to define an electrically isolated area or raceway portion 1019 a along a perimeter or border region or portion 1012 b of the front substrate 1012, while the conductive layer 1020 on the rear substrate 1014 includes a deletion line 1021 to define an electrically isolated area or raceway portion 1021 a along a perimeter or border region or portion 1014 b of the rear substrate 1014. A conductive material or bridge 1023 a (such as a conductive epoxy, film, frit, paste or the like) is disposed along the perimeter or border region 1012 b and between the electrically isolated area 1019 a and the conductive layer 1020 of rear substrate 1014, while a second conductive material or bridge 1023 b (such as a conductive epoxy, film, frit, paste or the like) is disposed along the opposite perimeter or border region 1014 b and between the electrically isolated area 1021 a and the semi-conductive layer 1018 of front substrate 1012.

As can be seen in FIGS. 33B and 33C, the rear substrate 1014 includes a pair of notches 1025 a, 1025 b to provide for electrical contact to the respective conductive bridges 1023 a, 1023 b. As best shown in FIG. 33C, an electrical connector or contact (not shown) may engage or contact the conductive bridge 1023 a at the notch or cut away 1025 a, whereby the conductive bridge 1023 a may function as an electrical raceway along the border region 1014 c of rear substrate 1014, while the electrically isolated area 1019 a and deletion line 1019 of border region 1012 b of front substrate 1012 substantially precludes electrical power from reaching the semi-conductive layer 1018 along the rear surface 1012 a of front substrate 1012. Likewise, another electrical connector or contact may engage or contact the conductive bridge 1023 b at the notch or cut away 1025 b, whereby the conductive bridge 1023 b may function as an electrical raceway along the border region 1012 c of front substrate 1012, while the electrically isolated area 1021 a and deletion line 1021 of border region 1014 b of rear substrate 1014 substantially precludes electrical power from reaching the conductive layer 1020 along the front surface 1014 a of rear substrate 1014.

Referring now to FIG. 34, an electro-optic or electrochromic cell or reflective element assembly 1110 includes a front substrate 1112 and a rear substrate 1114 with an electro-optic or electrochromic medium 1116 sandwiched between a semi-conductive layer or coating (such as ITO or the like) 1118 on the rear surface 1112 a of the front substrate 1112 and a conductive layer or coating (such as silver, silver alloy, or the like) 1120 on the front surface 1114 a of the rear substrate 1114. A perimeter seal 1117 is disposed around the electrochromic medium 1116. The front substrate 1112 includes an opaquifying or darkening or blackening or concealing or hiding non-conductive border coating 1119 disposed around the perimeter regions or border of the rear surface 1112 a. The border coating 1119 may comprise a decorative and/or color matching coating, and may be colored to match the body color, the color of the mirror case or the color of the electrochromic medium in its night state, or any other desired color. The transparent semi-conductive coating or layer 1118 is disposed on the rear surface 1112 a of front substrate 1112 and may at least partially overlap the non-conductive border coating 1119, at least along one border region 1112 b of the front substrate 1112, such as shown in FIG. 34.

Reflective element assembly 1110 includes an electrical connector 1122 that may be disposed at a perimeter or border region 1110 a of the reflective element assembly for providing or delivering electrical power to the semi-conductive layer 1118 of front substrate 1112 via a conductive bridge or adhesive 1123 a. As can be seen in FIG. 34, the connector 1122 is formed to overlay the rear surface 1114 b of rear substrate 1114 and extend along an edge 1114 c of the rear substrate and contact the conductive bridge 1123 a disposed between the connector 1122 and the semi-conductive layer 1118 and outside of the perimeter seal 1117 at the overhang region 1112 g. The conductive layer 1120 may not extend fully across the front surface 1114 a of rear substrate 1114 at the connector 1122, so that a non-conductive glass surface 1114 e is defined along the perimeter edge portion or region 1114 c of rear substrate, whereby a gap is defined between the connector 1122 and conductive layer 1120. The non-conductive glass surface 1114 e or gap and the non-conductive perimeter seal 1117 function to electrically isolate or insulate the connector 1122 from conductive coating 1120 of rear substrate 1114 to preclude shorting of the electrochromic cell or reflective element assembly.

Likewise, a second electrical connector 1124 may be disposed on another perimeter region 1110 b of the reflective element and may be formed to overlay the rear surface 1114 b of rear substrate 1114 and extend along an edge 1114 d of the rear substrate and contact the conductive bridge 1123 b disposed between the connector 1124 and the conductive layer 1120 and outside of the perimeter seal 1117. The conductive layer or coating 1118 of front substrate 1112 may not extend fully across the surface 1112 a of front substrate 1112 so as to define a non-conductive surface or area of border coating 1119 at conductive bridge 1123 b and generally at the overhang region 1112 f. The second surface 1112 a of front substrate 1112 and the non-conductive border coating 1119 and non-conductive seal 1117 function to electrically isolate or insulate the connector 1124 and conductive adhesive 1123 b from the conductive coating 1118 of front substrate 1112. The second connector 1124 may provide electrical power to the metal reflector coating or conductive layer 1120 on the rear substrate 1114, with the conductive adhesive 1123 b acting as a raceway along a perimeter or border region of the front surface of the rear substrate 1114. The connectors 1122, 1124 may be connected to an appropriate power source, control, circuitry or the like for controlling the electrochromic cell or reflective element assembly.

Optionally, and as shown in FIG. 35, an opaquifying non-conductive border coating or layer 1119′ may be disposed along the front surface 1112 c of front substrate 1112 to provide a decorative border coating along the perimeter or border regions of the front surface 1112 c of front substrate 1112. The transparent semi-conductive coating or layer 1118′ thus may be disposed on the rear surface 1112 a of front substrate 1112 in a generally uniform thickness and may coat the border region 1112 b, but may not extend to the border region 1112 d, thereby defining a non-conductive area or electrically isolated area or non-conductive glass surface 1112 e at the border region 1112 d. The non-conductive glass surface 1112 e and non-conductive seal 1117 function to electrically isolate or insulate the conductive coating 1118 of front substrate 1112 from connector 1124 and conductive adhesive 1123 b generally at the overhang region 1112 f. Likewise, and as described above, the conductive coating 1120 may not extend to the edge 1114 c of rear substrate 1114 to define a non-conductive glass surface 1114 e at and adjacent to connector 1122, so that connector 1122 is electrically isolated and insulated from conductive coating 1120 by non-conductive surface 1114 e and non-conductive seal 1117. Optionally, and as shown in FIG. 36, an opaquifying border 1119″ may be embedded in the border regions 1112 b′, 1112 d′ of the front substrate 1112′, such as via a radiation induced coloration in the glass of the substrate or via other means or processes.

Referring now to FIG. 37, an electro-optic or electrochromic cell or reflective element assembly 1210 includes a front substrate 1212 and a rear substrate 1214 with an electro-optic or electrochromic medium 1216 sandwiched between a semi-conductive layer or coating (such as ITO or the like) 1218 on the rear surface 1212 a of the front substrate 1212 and a conductive layer or coating (such as silver, silver alloy, or the like) 1220 on the front surface 1214 a of the rear substrate 1214. The conductive coating 1220 of rear substrate 1214 does not extend fully to the edge 1214 c of substrate 1214, so that a non-conductive glass surface or area or region 1214 e is defined on surface 1214 a along the perimeter portion at edge 1214 c. A non-conductive perimeter seal 1217 is disposed around the electrochromic medium 1216 and may at least partially or substantially fill or cover or encompass the non-conductive glass surface 1214 e. The non-conductive glass surface 1214 e and non-conductive seal 1217 thus function to electrically isolate or insulate the conductive coating 1220 from the connector 1222 and conductive adhesive 1223 a.

The front substrate 1212 includes an opaquifying or darkening or blackening or concealing or hiding non-conductive border coating 1219 a disposed over the semi-conductive layer 1218 and around or along a perimeter region or border 1212 b of the rear surface 1212 a of the front substrate 1212, and an opaquifying conductive border coating 1219 b disposed over the semi-conductive layer 1218 and around or along a perimeter region or border 1212 c of the rear surface 1212 a of the front substrate 1212. The transparent semi-conductive coating or layer 1218 may include a deletion line 1221 to define an electrically isolated area or region 1221 a, with the non-conductive border coating 1219 a disposed along the semi-conductive layer 1218 and over the deletion line 1221. The non-conductive border coating 1219 a may at least partially or substantially fill in or encompass deletion line 1221. The non-conductive border coating 1219 a and deletion line 1221 thus function to electrically isolate or insulate the conductive coating 1218 from electrical connector 1224.

In the illustrated embodiment, the reflective element assembly 1210 includes an encapsulant 1225 which substantially surrounds the rear and side edges of the reflective element assembly and may cover or overlay a heater pad or the like 1227 at the rear surface 1214 b of the rear substrate 1214. The encapsulant 1225 extends along the edges 1214 c, 1214 d of rear substrate 1214, and further at least partially along the perimeter edges 1212 d, 1212 e of front substrate 1212. A metal connector 1222 may be provided through the encapsulant 1225 to power or energize the semi-conductive layer 1218 on rear surface 1212 a of front substrate 1212 via a conductive bridge or epoxy or adhesive 1223 a disposed at least partially around the connector 1222 and between the connector 1222 and the opaquifying conductive border coating 1219 b. As can be seen in FIG. 37, the connector 1222 may be disposed generally within the conductive bridge 1223 a and the non-conductive glass surface 1214 e and non-conductive seal 1217 may separate or isolate the connector 1222 and conductive bridge 1223 a from the conductive layer or coating 1220 of rear substrate 1214, in order to avoid contact or electrical communication between the connector 1222 and the conductive layer 1220 on front surface 1214 a of rear substrate 1214.

Likewise, the metal connector 1224 may be provided through the encapsulant 1225 to power or energize the conductive layer 1220 on front surface 1214 a of rear substrate 1214 via a conductive bridge or epoxy or adhesive 1223 b disposed at least partially around the connector 1224 and between the connector 1224 and the opaquifying conductive border coating 1219 a, and further between the opaquifying conductive border coating 1219 a and the conductive layer 1220. The non-conductive border coating 1219 a and deletion line 1221 thus serve to electrically isolate the connector 1224 and conductive bridge 1223 b from conductive layer or coating 1218 of front substrate 1212.

Optionally, and with reference to FIG. 38, the conductive bridge or adhesive 1223 b′ may be disposed at the overhang regions 1212 f, 1212 g of the front substrate 1212, with the perimeter seal 1217′ disposed generally flush with the edges 1214 c, 1214 d of the rear substrate 1214. As can be seen in FIG. 38, the connectors 1222, 1224 may be positioned generally within the respective conductive bridges 1223 a, 1223 b′, whereby the electrical contact to the conductive coating 1219 b (and the semi-conductive layer 1218′) and to the conductive layer 1220 is through the respective conductive bridges 1223 a′, 1223 b′. The conductive metallic reflector layer 1220 on front surface 1214 a of rear substrate 1214 may not be applied at the outer perimeter region of the front surface 1214 a to provide a non-conductive glass surface or region or area 1214 e at or near or adjacent to the connector 1222 and conductive bridge 1223 a′ to electrically isolate or insulate connector 1222 and conductive bridge 1223 a′ from conductive layer 1220 of rear substrate 1214.

The conductive bridge 1223 b′ may contact the conductive layer 1220 along an edge portion 1220 a of the conductive layer. Optionally, in such an embodiment, the edge portion 1220 a of the metallic reflector or conductive layer 1220 may wrap at least partially around the edge dimension 1214 d of the rear substrate 1214 to extend partially along the edge 1214 d, and the encapsulant 1225 may provide a cavity 1225 a partially along the edge 1214 d for receiving the conductive bridge or epoxy or adhesive or paste or frit or the like 1223 b′ to provide contact to the conductive layer 1220 along the wrapped edge portion 1220 a of the conductive layer 1220 to enhance the electrical contact and conductivity from the connector 1224 to the conductive layer 1220. The reflective element assembly 1210′ thus may provide an enlarged electro-optic or electrochromic region of the reflective element assembly by reducing the conductive bridge region for the conductive adhesive or bridge 1223 b′.

Therefore, the present invention provides an electro-optic or electrochromic reflective element assembly that provides electrical contact to electrical raceways or conductive layers or coatings along regions or border or perimeter regions of the assembly that have a restricted overhang. The electrical connections may be made at overhang regions of the front substrate where the perimeter regions of the front substrate extend beyond the corresponding perimeter regions of the rear substrate, such that the electrical connectors are not viewable through the front surface of the front substrate. The present invention thus may provide a reduced or minimal bezel or no bezel assembly and may provide enhanced performance of the electrochromic mirror assembly. The conductive epoxy or adhesive or bridge may provide an electrical raceway along a perimeter or border portion of the semi-conductive and/or conductive layers of the substrates to provide rapid electrical flow along the layers or coatings to further provide rapid and substantially uniform darkening or coloring of the electrochromic medium. The connectors and bridges of the present invention facilitate such enhanced performance at a restricted overhang region and thus provide for a minimal bezel or no bezel around the perimeter of the reflective element assembly. The electrical connectors are electrically isolated or insulated from the other conductive layer or coating via a non-conductive surface and non-conductive seal being positioned between the connector and the respective other conductive layer.

In the embodiments described above, it is envisioned that the non-conductive glass surfaces (where applicable) may be formed by masking the surface of the substrate during coating or deposition of the conductive layer or coating, or may be formed by etching (such as laser etching, chemical etching, mechanical etching or the like) or otherwise removing the conductive layer or coating at the desired area or region, such as via a high voltage discharge to remove or burn the coating off of the desired area or region. The masked portion or etched portion or non-conductive portion may be generally at the outer perimeter or edge of the coating, and may have a width of approximately 0.05 mm, or approximately 0.1 mm, or up to approximately 1 mm. The masked portion or non-conductive surface may be partially or substantially filled or encompassed by the non-conductive seal or by other non-conductive layers or the like disposed at the surface of the substrate. Likewise, the deletion lines (where applicable) may be formed on and through the respective conductive or semi-conductive layer to define electrically isolated areas or regions of the layers. The deletion lines may be formed via any known manner, such as via chemical etching, mechanically etching or, and preferably, laser etching of the layers. The size or width of the deletion line is selected to be sufficient to create an electrical break so there is no electrical conductivity between the layer and the electrically isolated region of the layer. Typically, the deletion lines may be formed to be approximately 0.01 mm to approximately 0.5 mm or thereabouts.

Also, the perimeter seal that generally surrounds the electrochromic medium and spaces the front and rear substrates may have a width of preferably approximately 0.5 mm to approximately 3 mm, more preferably approximately 1 mm to approximately 2 mm, and most preferably approximately 1.25 mm to approximately 1.75 mm. The overhang that is defined at the edges of the substrates (where, for example, the rear substrate may be smaller than the front substrate) may be preferably approximately 0.1 mm to approximately 2 mm, more preferably approximately 0.25 mm to approximately 1.5 mm, and most preferably approximately 0.75 mm to approximately 1.25 mm.

In addition to other materials to be used as conductive busbars (such as silver frit, paste, conductive inks, and/or the like), optionally, ultrasonic soldering techniques may be used to apply a busbar which consists of solder (typically, standard soldering technique may not provide good adhesion/flow between the solder and a glass substrate). The solder can be used to provide a busbar for an semi-conductive coating (such as ITO or the like) or for a metallic coating. For example, an ultrasonic soldering system made by Asahi Glass company of Japan (e.g., Model: Sunbonder USM-3) may be used for applying this special solder. The solders that may be used include, for example, ultrasonic solders 143 and 297, available from Asahi Glass company. However, other materials may be implemented, such as conductive inks, pastes, frits, and the like, without affecting the scope of the present invention.

Optionally, and with reference to FIG. 39, the rear or smaller substrate 1314 of an electro-optic or electrochromic cell or reflective element assembly 1310 may be formed to have a tab out portion or protrusion 1314 a along one edge. The electro-optic or electrochromic medium may then be injected through an opening or gap in the perimeter seal 1317 (that spaces the front substrate 1312 from the rear substrate 1314) that generally corresponds with the outward protrusion 1314 a of the rear substrate 1314. A plug is applied or inserted into the gap to seal the electrochromic medium within the perimeter seal and the substrates after the electrochromic medium is injected. Typically, such plugs may be difficult to insert in non-flush edges of mirror cells because they may be visible if they are inserted too far into the gaps in the seals. The tab out portion 1314 a of the rear substrate 1314 provides an edge portion that is generally flush with the front substrate to provide a larger area for the plug to be positioned at without having the plug insert into the area where it may be visible to a user of the mirror assembly. Optionally, an opaquifying or hiding or darkening layer of the reflective element assembly (if applicable) may be expanded in that area to cover or conceal or hide the plug and tab out portion.

Optionally, the electro-optic or electrochromic cell or reflective element assembly of the present invention and the electrical connectors thereon or therearound may be coated with a protective coating to limit or reduce corrosion that may occur on the electrical connectors over time. The coating may comprise a parylene coating or parylene C coating or the like to enhance corrosion resistance (or may comprise other known parylene coatings, such as a parylene N coating, a parylene D coating or a parylene HT coating or the like). Such a parylene coating may be formed in a plasma chamber or vacuum applied and is highly penetrating or permeating so that the parylene coating may penetrate and surround the metal electrical clips or pins or connectors and seal them to limit corrosion of the electrical components. The parylene coating may comprise a thin coating (such as, for example, approximately 2.5 μm to about 12.5 μm) which coats and permeates anything placed in the chamber and not otherwise covered or masked. The parylene coating may comprise a vacuum applied polymer that is either in a gaseous or solid state, and may possess substantial dielectric and barrier properties per unit thickness. Such parylene coatings are known and are typically used in position sensor applications, intake manifold pressure sensor applications, gas sensor applications and valve cover gasket applications for vehicles.

For example, an electrical clip or connector may be in contact with the semi-conductive or conductive layer and may be susceptible or vulnerable to corrosion at the point where the two come in contact (particularly in a high moisture or salt environment and particularly for exterior rearview mirror assemblies). A parylene coating may be applied to substantially seal the connector at the semi-conductive or conductive layer to resist such corrosion. The electrochromic cell or reflective element assembly (with electrical contacts or connectors attached thereto) may be placed in a chamber and the parylene coating may be applied, such as via a vacuum vapor deposition process or the like. Optionally, two or more cells may be stacked in a stepped or offset manner, such that the edges of each cell are exposed to the parylene coating, while the above and below cell act as a mask over the rest of the cell. The parylene coating thus may only be applied to the offset area. The cells of the stack of cells thus may act as a self masking element for the other cells of the stack. Such a self masking approach with multiple cells may be particularly useful for parylene coatings because of the amount of time that it typically may take to coat an item with such parylene coatings.

The parylene raw material (di-para-xylylene dimer) is a crystalline powder and may be vaporized at approximately 150 degrees C. and then molecularly cleaved or pyrolyzed at approximately 680 degrees C. This forms the para-xylylene, which may be introduced generally at room temperature into a vacuum deposition chamber as a monomeric gas that polymerizes substantially evenly on the substrates. The coating then grows as a conformal film on all of the exposed surfaces, edges, etc. of the substrates or cells.

Testing has shown that a known conventional corrosion protection coating or seal may allow corrosion of the electrical contacts and failure of the mirror after about 12 weeks in a salt spray test chamber (such as a test chamber conducting tests in accordance with ASTM B-117, which is hereby incorporated herein by reference), while a substantially identical or similar mirror coated with a parylene C coating may be substantially unchanged, with the electrical contacts remaining at least substantially uncorroded, after about 22 weeks in the same salt spray test chamber and undergoing the same salt spray test. The parylene coating thus provides substantial enhancement of corrosion resistance and the mirror reflective element life cycle over known mirror corrosion protection means.

Optionally, the mirror assemblies or reflective element assemblies or cells of the present invention may include one or more displays for displaying information to the driver or occupant of the vehicle. Optionally, the conductive or semi-conductive layers of the reflective element assembly may have a metallic layer which may be absent or removed at portions, such as to create a local window for placement therebehind of a light emitting display, such as a compass display or PSIR display or other informational display or the like, such as a display of the type disclosed in commonly assigned U.S. Pat. Nos. 6,222,460 and 6,326,900, which are hereby incorporated herein by reference in their entireties, but while maintaining at least the underlying semi-conducting layer at the local window region so that electrical connection through the electrochromic medium at that local region is sustained.

Optionally, the reflective element assembly of the present invention may include other display systems or elements (not shown) which are operable to provide, emit or display information or light through the reflective element assembly. The light is emitted through the reflective element assembly at a display area, such that the display information or light is viewable by a driver of the vehicle. The second or rear substrate and the respective semi-conductive layers of the reflective element assembly or cell then comprise a transflective one way mirror, such as disclosed in commonly assigned U.S. patent application Ser. No. 10/054,633, filed Jan. 22, 2002 by Lynam et al. for VEHICULAR LIGHTING SYSTEM, now U.S. Pat. No. 7,195,381, which is hereby incorporated herein by reference. Preferably, the reflective element assembly (behind which the display is disposed so that the information displayed is visible by viewing through the reflective element assembly) of the mirror assembly comprises a transflective mirror reflector or reflective element assembly such that the mirror reflective element assembly is significantly transmitting to visible light incident from its rear (i.e., the portion furthest from the driver in the vehicle), while simultaneously, the mirror reflective element assembly is substantially reflective to visible light incident from its front (i.e. the position closest to the driver when the mirror assembly is mounted in the vehicle, such as is disclosed in U.S. patent application Ser. No. 09/793,002, filed Feb. 26, 2001 by Schofield et al. for VIDEO MIRROR SYSTEMS INCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268; and/or in U.S. Pat. Nos. 5,668,663 and 5,724,187, the entire disclosures of which are hereby incorporated by reference herein.

The display system preferably comprises a display-on-demand type of display and includes a display element or light emitting device (also not shown) positioned at the back or fourth surface of the rear substrate. The display element is operable to emit light, such as in the form of indicia, alphanumeric characters, images, or the like, in response to a control or input. The display element may be a vacuum fluorescent (VF) display, a light emitting diode (LED), an organic light emitting diode (OLED), a gas discharge display, a plasma display, a cathode ray tube, a backlit active matrix LCD screen, an electroluminescent display, a field emission display or the like, without affecting the scope of the present invention. The particular display element may be selected to provide a desired color to the display. For example, a VF display may be selected to provide a blue-green color or other colors to the information displayed (depending on the phosphor selected for the display), while a light emitting diode may be selected to provide other colors, such as reds, ambers, or other colors.

Preferably, the display is a display-on-demand type of display, such as of the types disclosed in commonly assigned U.S. Pat. Nos. 5,668,663 and 5,724,187, and/or in U.S. patent application Ser. No. 10/054,633, filed Jan. 22, 2002 by Lynam et al. for VEHICULAR LIGHTING SYSTEM, now U.S. Pat. No. 7,195,381; and/or Ser. No. 09/793,002, filed Feb. 26, 2001 by Schofield et al. for VIDEO MIRROR SYSTEMS INCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268, which are all hereby incorporated herein by reference. With such a display, it is not only desirable to adjust the display brightness according to ambient lighting conditions, but it is also desirable to adjust the display brightness such that a sufficient contrast ratio is maintained against the variable background brightness of the reflected scene. Also, it may be desirable to compensate for changes in transmission of the electrochromic device affected to control rearward glare sources, in order that the display brightness appears to be maintained at a generally constant level.

In certain conditions, the ambient light intensity within the cabin of the vehicle may be sufficiently high so that reflected light from the mirror reflective element and, in particular, from the display region, tends to “wash-out” the display. It is envisioned that this glare may be reduced by taking advantage of the electrochromic function of the mirror assembly. More particularly, the electro-optic or electrochromic medium of the electro-optic or electrochromic reflective element assembly may be colored or darkened in the area of the display by constructing a locally addressable region across the display. This may be achieved by creating a deletion line in the second surface semi-conductive layer at the second surface of the first or front substrate and/or in the third surface semi-conductive layer of the rear substrate, hence breaking electrical continuity from the rest of the electrochromic cell. An ambient light sensor (not shown) may be used to detect the critical ambient light levels at which “wash-out” is a problem. The addressable region may then be separately colored or darkened to the appropriate level to reduce the glare from the display area in response to the ambient light sensor. Although such a glare problem could be solved by coloring the entire mirror, by localizing the region of coloration to only the display area, the electrochromic mirror assembly of the present invention allows the rest of the mirror reflective area, which does not incorporate the display, to retain full reflectivity while the display area is colored or darkened (such as may be useful when driving by day).

In order to maintain easy viewing of the display, it is desirable to adjust the display intensity in response to ambient light levels (in order to avoid washout during daytime driving conditions and glare during nighttime driving conditions) and in response to the degree of transmissivity of the electrochromic reflective element. For example, in low lighting conditions, such as during the nighttime, the intensity of the display may be dimmed to avoid glare, while in higher lighting conditions, such as during the daytime, the intensity of the display may be increased to provide sufficient visibility of the display to the driver of the vehicle. The mirror assembly may include light sensors for sensing the ambient light in the cabin of the vehicle or at the mirror assembly and may include a control which is operable to automatically adjust the display intensity and/or the transmissivity of the electrochromic medium in response to the ambient light sensors.

Further, automatic dimming circuitry used in electro-optic or electrochromic mirror assemblies utilizing the reflective element assemblies of the present invention may utilize one or more (typically two) photo sensors to detect glaring and/or ambient lighting. For example, a silicon photo sensor, such as a TSL235R Light-to-Frequency converter (available from Texas Advanced Optoelectronic Solutions Inc. of Plano, Tex.), can be used as such photo sensors. Such light-to-frequency converters comprise the combination of a silicon photodiode and a current-to-frequency converter on a single monolithic CMOS integrated circuit.

The reflective element assembly or assemblies of the present invention may also include or house a plurality of electrical or electronic devices, such as antennas, including global positioning system (GPS) or cellular phone antennas, such as disclosed in U.S. Pat. No. 5,971,552, a communication module, such as disclosed in U.S. Pat. No. 5,798,688, displays, such as shown in U.S. Pat. Nos. 5,530,240 and 6,329,925, blind spot detection systems, such as disclosed in U.S. Pat. No. 5,929,786 or 5,786,772, transmitters and/or receivers, such as garage door openers, a digital network, such as described in U.S. Pat. No. 5,798,575, a high/low head lamp controller, such as disclosed in U.S. Pat. No. 5,715,093, a memory mirror system, such as disclosed in U.S. Pat. No. 5,796,176, a hands-free phone attachment, a video device for internal cabin surveillance and/or video telephone function, such as disclosed in U.S. Pat. Nos. 5,760,962 and 5,877,897, a remote keyless entry receiver, map lights, such as disclosed in U.S. Pat. No. 5,938,321; 5,813,745; 5,820,245; 5,673,994; 5,649,756; or 5,178,448, microphones, such as disclosed in U.S. Pat. Nos. 6,243,003 and 6,278,377, speakers, a compass, such as disclosed in U.S. Pat. No. 5,924,212, a seat occupancy detector, a trip computer, an ONSTAR® system or the like (with all of the above-referenced patents commonly assigned to Donnelly Corporation, and with the disclosures of the referenced patents being hereby incorporated herein by reference in their entireties).

The reflective element assembly or assemblies of the present invention may include a printed circuit board (PCB), which may be attached to the rear surface (e.g. the fourth surface) of the mirror element by, for example, a suitable adhesive or the like. An example of such an arrangement is disclosed in commonly assigned U.S. Pat. No. 5,820,245, which is hereby incorporated herein by reference in its entirety. The PCB optionally may include glare sensing and ambient photo sensors and electrochromic circuitry that automatically dims the reflectivity of the electrochromic mirror element when glare conditions are detected, such as at nighttime or the like. Alternately, the PCB may be snap connected, by a clip or otherwise attached, to a plastic plate that itself is adhered to the electrochromic element.

The printed circuit board may include electronic or electrical circuitry for actuating the variable reflectance of the reflective element and for operating other electrical or electronic functions supported in the rearview mirror assembly. The circuit board may support, for example, light emitting diodes (LEDs) for illuminating indicia on display elements provided on the chin of the bezel of the mirror assembly or display devices provided on the reflective element, or map or dash board lights or the like. The circuit board may be independently supported from the reflective element or in the casing or may be mounted to the reflective element's rear or fourth surface on a separate plate or may be directly adhered to the rear surface by a suitable adhesive. Reference is made to U.S. Pat. Nos. 5,671,996 and 5,820,245, the disclosures of which are hereby incorporated herein by reference in their entireties.

Optionally, and as described in U.S. patent application Ser. No. 10/054,633, filed Jan. 22, 2002 by Lynam et al. for VEHICULAR LIGHTING SYSTEM, now U.S. Pat. No. 7,195,381, incorporated above, FIG. 40 describes a combined ground illumination/turn-signal indicator system 1600 suitable to use in an exterior mirror assembly of an automobile, and especially in smaller-sized exterior mirror assemblies, such as are used on, for example, a MY2002 Honda Accord or a MY2002 Toyota Camry or a MY2002 Acura Legend or a MY2002 Ford Taurus/Mercury Sable, and similar-sized passenger sedan vehicles. A lighting module 1650 comprises a plurality of five individual non-power LEDs 1620, 1622, 1624, 1626, 1628 (and that each, preferably, pass less than about 75 milliamps forward current when powered, more preferably each less than about 50 milliamps, and most preferably each less than about 30 milliamps) configured to emit angled light beams 1620 a, 1622 a, 1624 a, 1626 a, 1628 a generally rearwardly, horizontally and laterally away from the body side of the vehicle equipped with module 1650, and so as not to be substantially visible to the driver of the subject vehicle equipped with module 1650, and constituting a turn signal indicator signal visible to a driver approaching/overtaking the vehicle from the rear (i.e. traveling in the same direction in which the subject vehicle equipped with module 1650 is traveling) such as in a blind spot of the reflective element of the particular exterior mirror assembly that module 1650 is included in. Such an arrangement is disclosed in U.S. Pat. No. 5,669,705. Note that beams 1620 a, 1622 a, 1624 a, 1626 a, 1628 a project from the exterior mirror assembly generally horizontally to the road surface upon which the vehicle equipped with module 1650 is traveling. Module 1650 is optionally, and preferably, equipped with LED light source 1630 that is adapted to project light beam 1632 generally horizontally and directed away from the body side of the vehicle (and so function as a side-marker turn signal) and/or is equipped with LED light source 1640 that is adapted to project light beam 1642 generally horizontally and forwardly in the direction of travel of the vehicle equipped with module 1650 (and so function as a front turn signal).

Module 1650′ further includes a security light unit 1610′. As best seen in FIG. 41, security light assembly 1610′ projects a light beam 1615′ that is directed generally downward and at least generally rearward from the bottom of the driver-side or passenger-side exterior mirror assembly equipped with module 1650′ when mounted on the exterior of a vehicle (so as to illuminate the ground adjacent at least the front door and preferably adjacent the front and rear door of the side of the vehicle on which the exterior mirror assembly equipped with module 1650′ is mounted, in order to create a lighted security zone adjacent that side of the vehicle). Security light assembly 1610′ preferably comprises a single high-intensity power LED light source, and preferably a single high-intensity white light emitting LED light source such as the Luxeon™ Star Power LXHL-MW1A white light emitting diode described above, and preferably includes a heat sink and/or a reflector 1690′ and/or a lens 1696′, such as described above in connection with LED light module 1300. An electronic element 1695′ (that can comprise a load-dropping series power resistor and/or a direct current (DC) step-down conversion element and/or pulse width modulation circuitry) can be included in module 1610′ to allow connection of the preferred single LED light source in security light assembly 1610′ to the vehicle battery/ignition power supply (typically 12 volts DC nominal). Electronic element 1695′ preferably comprises an MC34063A control circuit or a National LM78S40 switching regulator or a MAX 1627 switching regulator.

Module 1650 preferably includes a unitary connector 1660 (FIG. 40) that allows connection of turn signal indicator LEDs 1620, 1622, 1624, 1626, 1628 and security light assembly 1610 to the vehicle wiring (so as, for example, to bring in the vehicle battery/ignition line and ground line to the electrical/electronic elements of module 1650) as a single-point-of-connect, thus facilitating electrical hook-up to the vehicle (such as by a single multi-pin plug/socket connection).

Module 1650 is preferably incorporated into an exterior mirror assembly as shown at 1750 in FIG. 42 (and such as disclosed in U.S. Pat. Nos. 6,276,821 and 5,669,705). A lighted exterior mirror system 1700 comprises a lighted exterior mirror assembly 1775 that includes a fixed portion 1725 adapted for attachment to vehicle exterior body portion 1780 and a movable portion 1778 that, preferably, includes a break-away joint to fixed portion 1725 (such as is disclosed in U.S. Pat. No. 5,371,659). Movable portion 1778 includes a housing portion 1723 that includes an exterior mirror reflective element 1730 (and preferably an electrochromic mirror reflective element, such as disclosed in U.S. Pat. Nos. 6,245,262; 6,154,306; 6,002,511; 5,910,854; 5,724,187; 5,668,663; 5,611,966; 5,500,760; 5,424,865; 5,239,405; and 5,233,461) that is mounted on an electrically-operated actuator (not shown) and that is located in a cavity 1770 formed by the walls of housing 1723. Module 1750 attaches to a lower portion of movable portion 1778 and comprises individual LED turn signal indicators 1720, 1722, 1724, 1726, 1728 (that each project a light beam generally horizontally and laterally away from body portion 1780 when the driver actuates a turn signal circuit of the vehicle, and that each, preferably, pass less than about 75 milliamps when powered, more preferably each less than about 50 milliamps and most preferably each less than about 30 milliamps) and further comprises a single high-intensity power LED security light assembly 1753 that projects a ground illumination light beam 1754 generally downwardly and at least rearwardly in order to create a lighted security zone, as described above with respect to security light assembly 1610′. Optionally, instead of single high-intensity power LED security light assembly 1753 (or in addition to), a single high-intensity power LED light module 1764 (preferably such as described in connection with module 1300 and that emits a ground illumination beam 1765 when powered in order to create a lighted security zone at entrances/exits to the vehicle equipped with assembly 1775) can be included in fixed portion 1725 of exterior mirror assembly 1775.

Note the use of an all-LED lighting system such as in module 1650 and module 1750 and in particular the combination of a plurality of individual lower-intensity (typically emitting less than 0.75 lumens and, more typically less than 0.5 lumens), lower current (less than 50 mA typically) non-power LEDs to form a turn signal indicator assembly and a compact (preferably less than about 20 mm cross-sectional diameter, more preferably less than about 15 mm, and most preferably less than about 10 mm) single high-intensity (luminous efficiency typically greater than about 1 lumen/watt, more preferably greater than about 3 lumens/watt, and most preferably greater than about 7 lumens/watt), high current (greater than 200 milliamps typically) power LED security light assembly in a common housing and forming a unitary sealed module is particularly well suited for exterior mirror assemblies of restricted size, and is particularly well suited for use in exterior mirror assemblies on mid-sized and compact sedan vehicles, where the width of the part of the mirror assembly that houses the exterior mirror reflective element has a width less than about 7.5 inches, more preferably less than about 6.5 inches, and most preferably less than about 5.5 inches. Also, in order to provide a compact combined turn signal/security light module for incorporation into an exterior mirror assembly, the combination of single high-intensity power LED source behind a linear row of lower-intensity individual non-power LED turn signal indicators, as best can be seen in FIG. 40, is advantageous.

Note also that a single high-intensity power LED turn signal assembly, such as those described above in connection with system 1400 and system 1500 can be combined with a single high-intensity power LED security light assembly (such as described in connection with module 1300) into a compact, sealed, unitary module that can be incorporated into an exterior mirror assembly.

A single high-intensity power LED lighting system 1800 suitable to use in the interior of a vehicle is shown in FIG. 43. An interior mirror assembly 1810 comprises a mirror housing 1808 that includes an interior mirror reflective element 1809 (preferably, an electrochromic reflective element). Mirror housing 1808 is pivotally adjustable about mirror support 1807 that is a two-ball support comprising two pivot joints 1804 a, 1804 b and a mirror mount 1805 that attaches via mirror mounting button 1803 to windshield portion 1802. A high-intensity single LED light module 1820 is included in the interior cavity formed by the walls of housing 1808 (and located at least partially behind reflective element 1809). Light module 1820 preferably includes a single high-intensity power LED light source 1850 that preferably is a white light emitting high-intensity LED such as the Luxeon™ Star Power LXHL-MW1A white light emitting diode described above. Light emitted by LED source 1850 (when powered) is shaped and directed by reflector 1840 and/or lens 1822 (as described above with respect to module 1300) to form light beam 1885 that preferably is of an intensity such as to illuminate a roughly 1 foot by 1 foot zone (such as at a lap area of a driver or front seat passenger in a vehicle in which mirror assembly 1810 is mounted) at a distance of about 20-40 inches and to an averaged light intensity of at least about 30 lux, more preferably at least about 50 lux, and most preferably at least about 75 lux. Such a high intensity single LED can function as a map light or reading light or courtesy light for a front seat occupant of the vehicle. LED light source 1850 is in thermal contact with a heat sink 1860 (fabricated of materials and preferably with heat dissipating elements, as previously described with respect to heat sink 1340). Vehicle battery/ignition power is provided to light source 1850 via a series power resistor 1870 that preferably has a power rating of at least about 2 watts, more preferably at least about 3 watts and most preferably at least about 4 watts. Preferably, heat sink 1860 functions as a heat sink/heat dissipater for heat generated within series power resistor 1870. Optionally, a direct current (DC) step-down voltage conversion element (such as an MC34063A control circuit or a National LM78S40 switching regulator or a MAX 1627 switching regulator) can be used as an alternate to, or in addition to, series power resistor 1870.

A single high-intensity power LED lighting system 1900 suitable to use in the interior of a vehicle is shown in FIG. 44. An interior mirror assembly 1910 comprises a mirror housing 1908 that includes an interior mirror reflective element 1909 (preferably, an electrochromic reflective element). Mirror housing 1908 is pivotally adjustable about mirror support 1907 that is a single-ball support comprising a single pivot joint 1904 and a mirror mount 1905 that attaches via a mirror mounting button 1903 to a windshield portion 1902. Note that, alternately, a header mounting to a header portion of the vehicle interior above the front windshield, as known in the automotive mirror art, can be used, without affecting the scope of the present invention. A single high-intensity LED light module 1920 is included in the interior cavity formed by the walls of housing 1908 (and preferably located at least partially behind reflective element 1909). Light module 1920 preferably includes a single high-intensity power LED light source 1950 that preferably is a white light emitting high-intensity LED such as the Luxeon™ Star Power LXHL-MW1A white light emitting diode described above. Light emitted by LED source 1950 (when powered) is shaped and directed by reflector 1940 and/or lens 1922 (as described above with respect to module 1300) to form light beam 1985 that preferably is of an intensity such as to illuminate a roughly 1 foot by 1 foot zone (at a lap area of a driver or front seat passenger in a vehicle in which mirror assembly 1910 is mounted) to an averaged light intensity of at least about 30 lux, more preferably at least about 50 lux, and most preferably at least about 75 lux. Such a high intensity single LED can function as a map light or reading light or courtesy light for a front seat occupant of the vehicle. LED light source 1950 is in thermal contact with a heat sink 1960 (fabricated of materials and preferably with heat dissipating elements as previously described with respect to heat sink 1340) that is combined with reflector 1940. Vehicle battery/ignition voltage and power is provided to light source 1950 via plug terminals 1971, 1972 that connect to a direct current (DC) step-down voltage conversion element 1970 (such as an MC34063A control circuit or a National LM78S40 switching regulator or a MAX 1627 switching regulator) that in turn connects to and feeds power (at a voltage typically in the about 1.5-5 volts range and at a current greater than about 100 milliamps, more preferably at least about 200 milliamps, and most preferably at least about 300 milliamps) to high-intensity LED light source 1950.

The system 1900′ shown in FIG. 45 is similar to that shown in FIG. 44, but with the high-intensity LED light module 1920′ of system 1900′ positioned in the mirror support 1907′ (sometimes referred to as the mirror bracket) of interior mirror assembly 1910′, and adapted to project an intense beam 1985′ of, preferably, white light down towards a lap area of an occupant of a front seat occupant of the vehicle.

Note that an LED light module such as described above could be included in a pod attaching to the interior mirror assembly or in an accessory module, such as are disclosed in U.S. Pat. Nos. 5,708,410; 5,576,687; 5,255,442; 4,930,742 and 4,807,096; and U.S. patent application Ser. No. 09/793,002, filed Feb. 26, 2001, now U.S. Pat. No. 6,690,268.

It should be understood from the foregoing that the present invention provides an improved non-incandescent light source unit/module suitable for use in a vehicle accessory, such as a lighted interior mirror assembly or a lighted exterior mirror assembly, including a ground illumination exterior mirror assembly, and in other interior lighting applications such as dome lights, rail lights, reading lights, or vanity lighting in a sunvisor. The unit is provided as a single or modular assembly that, preferably, can be directly and releasably mounted in the vehicle accessory, such as those disclosed in U.S. provisional applications, Ser. No. 60/263,680, filed Jan. 23, 2001; and Ser. No. 60,243,986, filed Oct. 27, 2000.

It should be understood from the foregoing that the present invention provides a high-intensity non-incandescent light source unit/module that, optionally, provides a one-for-one replacement for an incandescent light source in a vehicle accessory, such as a lighted interior mirror assembly or a lighted exterior mirror assembly, including a ground illumination exterior mirror assembly, and in other interior lighting applications such as dome lights, rail lights, reading lights, or vanity lighting in a sunvisor. The high-intensity LED lighting unit is provided as a single or modular assembly that can be directly and releasably plugged into a socket of an incandescent light source circuit, and be powered thereby, or can otherwise be incorporated into the vehicle accessory. Alternately, the light source unit/module of the present invention can be connected into other circuits that are connected to the vehicle ignition voltage supply. Furthermore, since LEDs do not typically generate the heat associated with incandescent light sources, more sensitive electronics which have either been heretofore relegated to exterior locations of the interior rearview mirror assembly, or to less desirable locations within the mirror assembly, may be located at more optimal positions within the mirror casing. Moreover, the mirror casing space proximate to the light source unit may be used to house heat sensitive devices, such as electronics.

Also, the present invention can be used for lighting for illumination purposes and the like, and especially for reading lights such as map reading lights, or for instrumentation/console lighting, provided in video mirror assemblies, rearview mirror assemblies, camera assemblies and/or accessory modules (and/or in other vehicular accessories, such as an exterior mirror assembly-mounted ground illumination/security light or in an exterior mirror assembly-mounted turn indicator or brake indicator signal light). Such accessories may include the high-intensity, high-current capability light emitting diodes such as the high-flux LEDs available from LumiLeds Lighting, U.S., LLC of San Jose, Calif. under the SunPower Series High-Flux LED tradename described above.

Suitable LEDs for the light sources of the present invention include a white light emitting light emitting diode, such as described in U.S. provisional applications, Ser. No. 60/263,680, filed Jan. 23, 2001; Ser. No. 60,243,986, filed Oct. 27, 2000; Ser. No. 60/238,483, filed Oct. 6, 2000; Ser. No. 60/237,077, filed Sep. 30, 2000; Ser. No. 60/234,412, filed Jul. 21, 2000; Ser. No. 60/218,336, filed Jul. 14, 2000; and Ser. No. 60/186,520, filed Mar. 2, 2000; and U.S. patent application Ser. No. 09/793,002, filed Feb. 26, 2001, now U.S. Pat. No. 6,690,268; and Ser. No. 09/585,379, filed Jun. 1, 2000, entitled “REARVIEW MIRROR ASSEMBLY WITH UTILITY FUNCTIONS”, including a thermostable LED, which emits the same color light even when the temperature varies. Thus, regardless of the interior or exterior temperature of the vehicle and/or of the accessory equipped with the thermostable non-incandescent light emitting diode source, the same color light is radiated. Such a thermostable white light emitting non-incandescent light emitting diode source can incorporate a trio of red, green, and blue fluorescent materials that together create white light when struck by 380 nm wavelength light from a gallium-nitride LED, and is available from Toyoda Gosei Co. and Toshiba Corp of Nagoya, Japan.

One suitable white light emitting diode (LED) that is thermostable is available from Toshiba America Electronic Components, Inc. of Irvine, Calif., Part Number: TLWA1100. The thermostable white-light LED integrates multiple colored phosphors and a short peak wavelength (preferably, approximately 380 nanometers (nm) in peak spectral output intensity) light-emitting diode junction in a phosphor-mixed transparent resin package to achieve a high luminosity, low power consumption light source. Such thermostable LEDs adopt a technological approach differing from that used in conventional LEDs. Light emission in the visible wavelength band is controlled by excited phosphors, not by using temperature changes in the LED to achieve a change in color output. The fact that the LED emission does not directly determine the color brings advantages in overall controllability and wavelength stability. Incorporated in vehicular accessories such as those disclosed above, the thermostable diode achieves improved tonic reproduction and enhanced color durability during temperature shifts. Such thermostable LEDs utilize a short wavelength light source by reducing the indium in an indium-doped GaN emission layer. This excites red, green, and blue (RGB) phosphors in the transparent resin of the device package to output white light. The RGB balance of the phosphor layer determines the output color, and different colored output can be achieved through modified phosphor balance. The emission light from the LED itself does not directly contribute to the white color. The phosphors used in the new LED offer excellent performance in terms of operating temperature range and color yield. Specifications of such thermostable white LEDs include a compact package (3.2×2.8 millimeter), provided in a Surface Mount Device (SMD). Luminosity is typically about 100 millicandela (mcd) at 20 mA and luminous flux/electrical watt is about 4.5-5.0 lumens per watt at 20 mA. Correlated color temperature is about 6,500-9,000K. Operating temperature is about −40 degrees Celsius-100 degrees Celsius and storage temperature is about −40 degrees-100 degrees Celsius.

Depending on the application, LEDs emitting a colored light can be used, such as high-intensity amber and reddish orange light emitting diode sources, such as solid state light emitting diode LED sources utilizing double hydro junction AlGaAs/GaAs Material Technology, such as very high-intensity red LED lamps (5 mm) HLMP-4100/4101 available from Hewlett Packard Corporation of Palo Alto, Calif., or transparent substrate aluminum indium gallium phosphide (AlInGaP) Material Technology, commercially available from Hewlett Packard Corporation of Palo Alto, Calif. Also, blue can be used, or a combination of individual different colored diodes, such as red, blue, white, green, amber, orange etc. can be used with color mixing thereof to form a desired color or to deliver a desired local intensity of illumination as noted above. Other suitable white emitting light-emitting diodes are available from Nichia Chemical Industries of Tokyo, Japan and from Cree Research Inc., of Durham, N.C. For example, a white light emitting diode is available from Nichia Chemical Industries of Tokyo, Japan under Model Nos. NSPW 300AS, NSPW 500S, NSPW 310AS, NSPW 315AS, NSPW 510S, NSPW 515S and NSPW WF50S, such as is disclosed in U.S. patent application Ser. No. 09/448,700, filed Nov. 24, 1999, now U.S. Pat. No. 6,329,925, and Ser. No. 09/244,726, filed Feb. 5, 1999, now U.S. Pat. No. 6,172,613. A variety of constructions are used including GaAsP on GaP substrate, gallium aluminum phosphide, indium gallium nitride, and GaN on a SiC substrate. Optionally, a plurality of LEDs, such as a cluster of two, three, four, six, eight or the like LEDs (each of the same color or the cluster comprising different colored LEDs), can be used to target and illuminate a local area for higher illumination at that area, such as may be useful in a map light or as a reading light or as an interior light or as an illumination source for an interior vehicle cabin-mounted and monitoring camera (most preferably illuminating the target area with white light). Such a cluster of high efficiency LEDs can be mounted at the mirror mount so as to project an intense pattern of light generally downwardly into the vehicle cabin for purposes of map reading, general illumination, courtesy illumination and the like. Also, a cluster of LED's, preferably including at least one white emitting LED and/or at least one blue emitting LED, can be mounted in a roof portion, side portion or any other portion of the vehicle cabin to furnish dome lighting, rail lighting, compartment lighting and the like. Use of white emitting LEDs is disclosed in U.S. Pat. No. 6,152,590, entitled “LIGHTING DEVICE FOR MOTOR VEHICLES”, filed Feb. 12, 1999, by Peter Fuerst and Harald Buchalla of Donnelly Hohe Gmbh & Co, KG.

As described above in connection with system 1400, it is sometimes desirable to mount a signal light behind the exterior mirror reflective element in the exterior mirror assembly, and such as is described in U.S. Pat. Nos. 6,166,848; 6,257,746; 6,045,243; and 5,788,357. Such incorporation of a signal light assembly such that the turn signal indicator light beam passes through the reflector of the reflective element (either by creating a local high transmission window in the reflector coating of the reflector of the exterior reflective element or by using a dichroic reflector) has the disadvantage of requiring a specialized reflective element specially adapted for this purpose. This approach is particularly disadvantageous for electrochromic exterior mirror reflective elements as dimming of the electrochromic medium in response to detected glare can also attenuate the intensity of the signal light beam(s) passing through the electrochromic medium.

An improved system 2000 whereby a turn signal element can be included in an exterior mirror reflective element assembly without the above disadvantages is shown in FIG. 46. An exterior mirror reflective element assembly 2150 comprises a bezel frame element 2100 (that typically comprises a molded polymeric structure, such as of a polypropylene material or an ABS material or an ASA material or a nylon material or the like). Exterior mirror reflective element assembly 2150 further comprises a principal exterior mirror reflective element 2120 (that provides the driver principally with a rearward field of view of other vehicles approaching from the rear in the side lane adjacent to the side of the vehicle that the exterior mirror assembly equipped with assembly 2150 is mounted to) and an auxiliary reflective element 2130 adapted to provide the driver with a field of view that extends laterally beyond that provided by reflective element 2120, and so as to function as a blind-spot mirror element. Exemplary constructions and materials suitable to use in assembly 2150 are disclosed in U.S. patent application Ser. No. 09/478,315, filed Jan. 6, 2000, now U.S. Pat. No. 6,522,451; and Ser. No. 09/745,172, filed Dec. 20, 2000, now U.S. Pat. No. 6,717,712.

Bezel frame element 2100 further includes a plurality of turn signal indicator elements 2102′, 2104′, 2106′, 2108′, 2110′, preferably located at a bezel frame element portion 2132 that separates and demarcates auxiliary reflective element 2130 (that preferably comprises a wide-angle mirror element and comprises a convex or aspheric metallic-reflective element, such as a chromium coated, bent glass or plastic substrate) from principal reflective element 2120 (that may be a flat, convex or aspheric mirror element, and that preferably comprises an electrochromic mirror element). Turn signal indicator elements 2102′, 2104′, 2106′, 2108′, 2110′ preferably comprise individual red light-emitting or amber light emitting LEDs such as those disclosed in U.S. Pat. Nos. 6,276,821 and 5,371,659. Turn signal indicator elements 2102′, 2104′, 2106′, 2108′, 2110′ are preferably mounted in bezel element 2100 at an angle so that the light beams emitted (beams 2102 a′, 2104 a′, 2106 a′, 2108 a′, 2110 a′ as shown in FIG. 47) are directed horizontally and laterally away from the side of the vehicle (preferably at an angle of at least about 15 degrees to the longitudinal axis of the vehicle) to which the exterior mirror assembly equipped with assembly 2150 is mounted, and so as not to be substantially visible to the driver of the subject vehicle (and so distract when operated at night), but be visible to a driver of another vehicle overtaking the subject vehicle from the rear.

Assembly 2150 is preferably supplied to an exterior mirror assembly manufacturer by a mirror reflective element manufacturer as a sealed module that includes the mirror reflective element(s), any load dropping resistor used in conjunction with the LED turn signal light source(s), any heater pad(s) used in association with the reflective element(s), any interconnection wiring and connector(s), and any backing plate element that attaches to a mirror adjustment mechanism such as an electrically-operated actuator, as is conventional. Thus, a unitary module can be supplied that allows an automaker choose to include a turn signal indicator into an exterior mirror assembly while impacting substantially only the mirror reflective element that detachably attaches to a mirror-adjustment mechanism.

As an alternate to using a plurality of lower-intensity, lower-current individual non-power LEDs as described above, a single high-intensity, high-current power LED can be used along with light piping, heat sinking and low heat-dissipation circuitry such as are described above. Also, turn signal indicator light sources can optionally be placed in alternate, or additional, locations in bezel frame 2100, such as portion 2133, 2134 or 2135 or elsewhere around bezel frame 2100. Further, a portion (such as portion 2132) or all of bezel frame element 2100 can be fabricated of a colored (such as red or amber), light-transmissive material (such as is conventionally used for automotive exterior brake and turn lights), and with the turn signal light sources located in the bezel element radiating from behind and through this colored, light-transmissive material. Also, instead of the dual reflective element assembly shown in FIG. 46, a single reflective element assembly (such as an electrochromic reflective element and assembly disclosed in U.S. Pat. No. 5,151,824) can be used, and with the individual turn signal light sources being located in the bezel that holds the reflective element into the reflective element assembly.

Also, where a heater pad (such as is disclosed in U.S. Pat. Nos. 5,446,576 and 5,151,824) is used in connection with an exterior rearview mirror reflector in an exterior mirror assembly equipped with a Luxeon™ Star Power high-intensity, high-current power LED system as disclosed herein, at least a portion of the resistive path/heater element that is comprised in such exterior mirror heater pads (that are typically used for defrosting ice and the like accumulated on the exterior of the mirror reflector during sub-zero temperatures) can be electrically connected in series with the high-intensity power LED used so that the heater pad serves as a voltage-dropping element for the power LED and so that any heat being dissipated is beneficially used to heat the exterior mirror reflector. In this regard, and referring to FIG. 48, improved lighted exterior mirror system 3700 comprises exterior mirror assembly 3780 (that attached to vehicle side body portion 3785). Exterior mirror assembly 3780 includes a ground illumination light source 3710 and a mirror reflective element 3782 that is heated by heater element 3784 (typically a PTC heater pad). Ground illumination light source 3710 illuminates when actuated by control 3750 (that is located in the vehicle) but only if not locked-out by lock-out 3730. Control 3750 actuates light source 3710 upon receipt of a signal from actuator 3760 (that, for example, may be a hand-held key fob that wirelessly communicates, such as by RF or IR communication, with control 3750 and such as is disclosed in U.S. Pat. No. 5,371,659; or it may be an actuator responsive to the proximity of approach of a person to the vehicle when parked or in response to actuation of a passive entry system of the vehicle). Once actuated by control 3750 (and assuming not locked-out by lock-out 3730 so as to prevent inadvertent actuation when the vehicle is being normally operated on a highway and not parked), light source 3710 illuminates to create a lighted security zone adjacent at least the front door on the vehicle side to which assembly 3780 is mounted until timeout 3740 times out (a timeout period of about 20 to 60 seconds typically, or longer if desired). Preferably, light source 3710 comprises a light emitting diode and preferably, a high-intensity, high-current capability power light emitting diode such as a high-flux LED available from LumiLeds Lighting, U.S., LLC of San Jose, Calif. under the SunPower Series High-Flux LED tradename. Such high intensity LEDs comprise a power package allowing high current operation of at least about 100 milliamps forward current, more preferably at least about 250 milliamps forward current, and most preferably at least about 350 milliamps forward current through a single LED. Such high current/high intensity LEDs (as high as 500 mA or more current possible, and especially with use of heat sinks) are capable of delivering a luminous efficiency of at least about 1 lumen per watt, more preferably at least about 3 lumens per watt, and most preferably at least about 5 lumens per watt. For applications such as ground illumination from exterior mirror assemblies and map/reading lighting from interior mirror assemblies or from windshield-mounted accessory modules such as windshield electronic modules or for ground illumination/camera-field-of-view illumination in association with video-based reverse-aids systems or park-aid systems or tow hitch-aid systems, it is preferable to use a single high-intensity power LED source having a luminous efficiency of at least about 7 lumens/watt; more preferably at least about 15 lumens/watt; and most preferably at least about 20 lumens/watt, with such single high efficiency power LED light source preferably being provided in a module that includes a heat sink/heat dissipater and most preferably, that further includes a power regulator such as a series power resistor and most preferably, a DC to DC voltage converter. Such high efficiency power LEDs are available from LumiLeds Lighting, U.S., LLC of San Jose, Calif. under the SunPower Series High-Flux LED tradename, for example. Preferably LED light source 3710 is connected in electrical series with heater element 3784 such that when vehicle battery voltage/vehicle ignition voltage (currently about 12V nominal but in future vehicles, about 42V nominal or a division thereof) is applied across the series combination, the difference between the desired forward voltage desired to operate light source 3710 and vehicle battery/ignition voltage is applied across heater element 3784 (or a portion thereof) such that heater element 3784 functions as a voltage divider and as a power dissipater that ballasts the application of vehicle battery/ignition voltage to light source 3710. By way of illustration, assume light source 3710 comprises a Luxeon™ Star Power white light power LED with a forward operating voltage of 2.5 volts and passing a forward current of 350 milliamps when operating. With such a light source, and with a 12V vehicle battery, the resistance of heater element 3784 (or a portion thereof) in series electrical connection with the LED light source is chosen to be 30 ohms so that when 350 milliamps is passed by the white light LED (and being in series therewith, also passed by the heater element or portion thereof), a voltage of 10.5 volts is dropped by the heater element (or portion thereof) that functions as a ballast to the high current white light LED. Consequently, power of 3.675 watts is dissipated by the heater element, which power can beneficially heat the mirror reflective element 3784 that heater element 3784 thermally contacts to heat (such as is desirable to remove condensation or frost or the like). Note that such an arrangement when used in a security lighting/ground illumination system such as disclosed in the '659 pat. referenced above has the advantage of providing a deicing/defrosting/heating of an exterior mirror reflective element before the driver enters the vehicle and/or the ignition is turned on (conventionally, such heater elements are actuated when the driver enters the vehicle and turns on the ignition). Thus, in the present invention, a driver approaching his or her vehicle can remotely, and at a distance, actuate the security lights in the exterior mirror assemblies on the vehicle, and for as long as these lights are actuated, the heater pads attached to the exterior mirror reflective element assemblies are dissipating energy, and are consequently heating the respective mirror reflective elements and assisting defrosting/demisting thereof. Optionally, heater pad 3784 (or a portion thereof) can be connected with the vehicle battery so that the full vehicle battery voltage is applied thereto (or to a portion thereof) but with such connection and application of the vehicle battery voltage being controlled by control 3750 such that a driver approaching his or her vehicle can remotely, and at a distance, actuate the security lights and/or the heater elements in the exterior mirror assemblies on the vehicle, and for as long as timeout 3740 has not timed-out, the heater pads attached to the mirror reflective elements in the exterior mirror assemblies are dissipating energy, and are consequently heating the respective mirror reflective elements and assisting defrosting/demisting thereof.

Optionally, and as described in U.S. Pat. No. 5,724,187, incorporated above, a mirror reflective element assembly 1401 may include front and rear substrates that may be flush or offset relative to one another. For example, and with reference to FIGS. 49 and 50A-C, an exposed portion of the conductive electrode coatings 1404, 1404′ may be provided through displacement in opposite directions relative to one another—i.e., laterally from, but parallel to, the cavity which is created by the substrates 1402, 1403 and the sealing means 1405 of the substrates 1402, 1403 onto which the bus bars may be affixed or adhered (see FIG. 50A). In addition, substrates 1402, 1403 may be off-set to provide an exposed portion of the conductive electrode coatings 1404, 1404′ through displacement in opposite directions relative to one another followed by perpendicular displacement relative to one another (see FIG. 50B). The dimensions of substrates 1102, 1103 may also be such that, for example, substrate 1402 may have a greater width and/or length than substrate 1403. Thus, simply by positioning substrates 1402, 1403 in spaced-apart relationship and so that their central portions are aligned will allow for peripheral edges of the substrate with greater dimensions to extend beyond the peripheral edges of the substrate with smaller dimensions. Thus, a portion of conductive electrode coating 1404 or 1404′ will be exposed, depending on whichever of substrates 1402, 1403 is dimensioned with a larger width and/or length (see FIG. 50C).

An exposed portion of the conductive electrode coatings 1404, 1404′ may also be provided in a flush design, where the substrates 1402, 1403 are sized and shaped to like dimensions. In such a flush design, the first substrate 1402 and the second substrate 1403 may each be notched at appropriate positions along their respective edges. The notches so provided present convenient areas for bus bars and/or point contacts to which are connected or affixed electrical leads 1410 for the introduction of an applied potential thereto.

It may also be desirable to apply a layer of reflective material onto the inward surface of substrate 1403, and with substrate 1403 notched in at least one appropriate position along its edges. In this way, direct access is available to the conductive electrode coated inward surface of substrate 1402. Likewise, substrate 1402 may be notched at a position appropriately spaced from the notch or notches on substrate 1403 to provide access to the conductive electrode coated inward surface of substrate 1403. These notches provide convenient areas for electrical leads to be connected or affixed, and allow for such connection or affixation to be made within the overall dimensions of the mirror assembly. For example, one or both of the substrates 1402, 1403 may be notched along one or more edges, and bus bars may then be affixed over the exposed portion of conductive electrode coatings 1404, 1404′ of substrates 1402, 1403. Electrical leads may then be joined to the bus bars. The electrical connection may be made to the inward surfaces of substrates 1402, 1403 without requiring further electrical connection on the peripheral edge of the mirror assembly. As such, the electrical connection to conductive electrode coatings 1404, 1404′ will be hidden from view by the reflective element and/or the mirror case or housing.

Alternatively, one or more localized lobe(s) may be provided at appropriate positions along the respective edges of substrates 1402, 1403 to facilitate direct access to the conductive coated inward surfaces of substrates 1402, 1403.

The bus bars may also comprise thin metal films, preferably with a thickness within the range of about 500 Å to about 50,000 Å or greater. These thin metal film bus bars may be deposited onto conductive electrode 1404 and/or 1404′ by vacuum deposition, such as by evaporation or sputtering, and typically have a width within the range of about 0.05 mm to about 6 mm (and preferably with a thickness in the range of 0.05 μm to about 5 μm or greater) and are inboard from the perimeter edge of the substrate.

To form the thin metal film bus bars, a mask may be affixed over the central region of the substantially transparent conductive electrode coated substrate leaving at least a portion, and preferably most, of the perimeter region unmasked. Then a thin film of metal, such as chromium and/or silver, or other metals such as copper, titanium, steel, nickel-based alloys, and the like, may be deposited using a vacuum deposition process across the entire surface, coating both the masked central region and the unmasked perimetal region. Thereafter, the mask may be removed leaving the central region of the substrate transparent and with a conducting thin metal film bus bar deposited on at least a portion of the perimetal region. For manufacturing economy, it may be desirable to establish thin metal film bus bars on the inward surface of substrate 1402, conductive electrode coating 1404′ and electrochromic solid film 1407 in a unitary vacuum deposition process step. Thus, it may be convenient to overlay in central alignment, for example, substrate 1403 (being uncoated glass) onto the substantially transparent conductive electrode coated surface of substrate 1402, where substrate 1403 is sized and shaped 30 about 2 mm to about 4 mm smaller in both length and width than substrate 1402 (see e.g., FIG. 50C). A peripheral edge of substrate 1402 of about 2 mm to about 4 mm will then extend beyond the peripheral edge of substrate 1403. In this instance, substrate 1402 is made, for example, from ITO-coated glass, and substrate 1403 is made from clear soda-lime glass. With this configuration, a vacuum deposition process may be used to deposit a thin metal film and, optionally, a metal oxide thereover, across the entire surface.

Upon completion of the deposition process, the substrates 1402, 1403 may be separated from one another. The formation of a thin metal film bus bar consisting of a chromium/silver coating about the peripheral edge of substrate 1402 may then be seen where, because of its smaller dimensions, substrate 1403 has served the role of a mask to the major, central region of substrate 1402 during deposition. That is, when substrate 1403 is removed, the major, central region of substrate 1402 has not been coated during the deposition and the transparency of the major, central region of substrate 1402 is maintained. Because this thin metal film bus bar is highly conductive and extends about the entire periphery of substrate 1402, electric potential may be supplied by means of a point electrical contact (optionally with local removal of any metal oxide) without the need for a large metal clip or ribbon connector wire as has been conventionally used heretofore. Moreover, because the thin metal film bus bar consists of a chromium/silver coating it forms a highly reflective perimeter coating which may be used to conceal any seal and/or electrical connection for the electrochromic cell [See U.S. Pat. No. 5,060,112 (Lynam)].

Also, whether the sealing means 1405 is a single seal or a double seal, it may be desirable for the seal material to comprise a cured conductive adhesive so that the seal, or at least a portion thereof, may provide, in whole or at least in part, an electrical bus bar function around the perimeter of a substrate of the assembly. When using such a combined seal and bus bar, care should be taken to avoid electrically shorting the inward facing surfaces of substrates 1402 and 1403. To obviate this, a seal construction, such as that shown in FIG. 51A, may be used. With reference to FIG. 51A, substrates 1420 and 1430 are coated on their inwardly facing surfaces with electrical conductor electrodes 1420′ and 1430′. The substrates 1420, 1430 are mated together with the compound seal 1450. The compound seal 1450 includes a conducting seal layer 1450A (formed, for example, of a conducting epoxy such as is described below) and a non-conducting, electrically insulating seal layer 1450B (formed, for example, of a conventional, non-conducting epoxy), which serves to insulate the two conducting electrodes from electrically shorting via conducting seal layer 1450A. Since the compound seal 1450 essentially circumscribes the edge perimeter of the part, the conducting seal layer 1450A (to which electrical potential may be connected to via the electrical lead 1490) serves as an electrically conductive bus bar that distributes applied electrical power more evenly around and across the electrochromic medium (not shown) sandwiched between the substrates 1420 and 1430.

Where the electrical conductor electrode 1420′, 1430′ on at least one of the opposing surfaces of the substrates 1420, 1430 is removed (or was never coated) in the region of the peripheral edge (as shown in FIG. 51B), a unitary conducting seal (as opposed to 35 the compound seal of FIG. 51A) may be used. Reference to FIG. 51B shows the electrically conducting seal 1450A joining the electrical conductor electrode 1430′ on the surface of substrate 1430 to a bare, uncoated surface of opposing substrate 1420. Since the contact area of the conducting seal layer 1450A to the substrate 1420 is devoid of the electrical conductor electrode 1420′, the conducting seal layer 1450A does not short the electrodes 1420′ and 1430′. Conducting seal layer 1450A serves the dual role of bus bar and seal, yielding economy and ease in device fabrication and production. Conducting seal layer 1450A may form a single seal for the cell or may be one of a double seal formed, for example, when a conventional, non-conducting epoxy is used inboard of that conducting seal.

Such a construction is particularly amenable to devices, such as those depicted in FIG. 49. For instance, in a rearview mirror, a fixture can form a mask around the edge substrate perimeter, while an adhesion layer of chromium followed by a reflector layer of aluminum followed by an electrochromic layer of tungsten oxide are deposited. Once removed from such a coating fixture, the edges, as masked by the coating fixture, are uncoated and present a bare glass surface for joining via a conductive epoxy seal to an opposing transparent conductor coated substrate. In such a configuration, the conductive seal can serve as a bus bar for the transparent conductor coated substrate it contacts without shorting to the reflector/adhesion layers on the opposite substrate.

As described supra, it may be advantageous to construct electrochromic mirrors whose reflective element is located within the laminate assembly. This may be achieved by coating the inward surface of substrate 1403 with a layer of reflective material, such as silver, so that the silver coating (along with any adhesion promoter layers) is protected from the outside environment. For example, a layer of reflective material may be vacuum deposited onto the inward surface of substrate 1403 in one and the same process step as the subsequent deposition of the electrochromic solid film 1407 onto substrate 1403. This construction and process for producing the same not only becomes more economical from a manufacturing standpoint, but also achieves high optical performance since uniformity of reflectance across the entire surface area of the mirror is enhanced. The thin film stack [which comprises the electrochromic solid film 1407 (e.g., tungsten oxide), the layer of reflective material (e.g., silver or aluminum) and any undercoat layers between the layer of reflective material and substrate 1403] should have a light reflectance within the range of at least about 70% to greater than about 80%, with a light transmission within the range of about 1% to about 20%. Preferably, the light transmission is within the range of about 3% to about 20%, and more preferably within the range of about 4% to about 8%, with a light reflectance greater than about 80%.

The inward facing surface of substrate 1403 may be coated with a multi-layer partially transmitting/substantially reflecting conductor comprising a partially transmitting (preferably, in the range of about 1% to about 20%)/substantially reflecting (preferably, greater than about 70% reflectance, and more preferably, greater than about 80% reflectance) metal layer (preferably, a silver or aluminum coating) that is overcoated with an at least partially conducting transparent conductor metal oxide layer [comprising a doped or undoped tin oxide layer, a doped or undoped indium oxide layer (such as indium tin oxide) or the like]. Optionally, an undercoating metal oxide (or another at least partially transmitting metal compound layer, such as a metal nitride like titanium nitride) may be included in the stack which comprises the multilayer conductor. This multi-layer conductor functions as the reflective element, and can be overcoated with electrochromic solid film 1407 during fabrication of an electrochromic mirror incorporating on demand displays.

Alternatively, the multi-layer conductor described supra may be used on the inward surface of substrate 1403, with the electrochromic solid film 1407 coated onto the inward surface of substrate 1402.

A light reflectance of at least 70% (preferably, at least 80%) for the reflective element to be used in an electrochromic mirror incorporating on demand displays is desirable so that the bleached (unpowered) reflectivity of the electrochromic mirror can be at least 55% (preferably, at least 65%) as measured using SAE J964a, which is the recommended procedure for measuring reflectivity of rearview mirrors for automobiles. Likewise, a transmission through the reflective element of, preferably, between about 1% to 20% transmission, but not much more than about 30% transmission (measured using Illuminant A, a photopic detector, and at near normal incidence) is desirable so that emitting displays disposed behind the reflective element of the electrochromic mirror are adequately visible when powered, even by day but, when unpowered and not emitting, the displays (along with any other components, circuitry, backing members, case structures, wiring and the like) are not substantially distinguishable or visible to the driver and vehicle occupants.

Optionally, the outermost surface of the substrate (i.e., the surface contacted by the outdoor elements including rain, dew and the like when, for example, the substrate forms the outer substrate of an interior or exterior rearview mirror for a motor vehicle constructed) can be adapted to have an anti-wetting property. For example, the outermost glass surface of an exterior electrochromic rearview mirror can be adapted so as to be hydrophobic. This reduces wetting by water droplets and helps to obviate loss in optical clarity in the reflected image off the exterior mirror when driven during rain and the like, caused by beads of water forming on the outermost surface of the exterior electrochromic mirror assembly. Preferably, the outermost glass surface of the electrochromic mirror assembly is modified, treated or coated so that the contact angle θ (which is the angle that the surface of a drop of liquid water makes with the surface of the solid anti-wetting adapted outermost surface of the substrate it contacts) is preferably greater than about 90 degrees, more preferably greater than about 120 degrees and most preferably greater than about 150 degrees. The outermost surface of the substrate may be rendered anti-wetting by a variety of means including ion bombardment with high energy, high atomic weight ions, or application thereto of a layer or coating (that itself exhibits an anti-wetting property) comprising an inorganic or organic matrix incorporating organic moieties that increase the contact angle of water contacted thereon. For example, a urethane coating incorporating silicone moieties (such as described in U.S. Pat. No. 5,073,012) may be used. Also, to enhance durability, diamond-like carbon coatings, such as are deposited by chemical vapor deposition processes, can be used as an anti-wetting means on, for example, electrochromic mirrors, windows and devices.

Double image performance in rearview mirrors is greatly assisted by the use of a vacuum-assisted sealing technique. An example of such a technique is a vacuum bag technique where, spacer means, such as spacer beads, are disposed across the surfaces of the substrates being mated, and a vacuum is used to better assure substrate to substrate conformity. It is preferable for at least one substrate (usually the first or front substrate) to be thinner than the other, and preferably for at least one substrate to have a thickness of 0.075″ or less, with a thickness of 0.063″ or less being more preferable, and with a thickness of 0.043″ or less being most preferable. This improvement in double image performance is particularly desirable when producing convex or multi-radius outside mirror parts, and when producing large area parts (such as, Class 8 heavy truck mirrors), and especially when vacuum backfilling is used in their production.

For exterior mirrors that have an area of at least about 140 cm², it is desirable to place at least some rigid spacer means (such as precision glass beads) at locations within the interpane space between the substrates in the laminate electrochromic cell. Preferably, such spacer beads are chosen to have a refractive index within the range of about 1.4 to about 1.6 so that they optically match the refractive index of the substrates (typically glass) and the electrolyte. These rigid spacer beads not only assist conformity and uniformity of interpane spacing, but also help maintain the integrity of peripheral seals on exterior rearview mirrors assemblies that use a liquid or thickened liquid. For instance, the peripheral seal may burst if an installer or vehicle owner presses on the mirror at its center and causes a hydraulic pressure build-up at the perimeter seal due to the compression of the fluid or thickened fluid at the part center. Use of such spacer beads, particularly when located at the center of the part within the interpane space, are beneficial in this regard whether the exterior rearview mirror is a flat mirror, convex mirror or multi-radius mirror, and is particularly beneficial when at least the first or front substrate (the substrate touched by the vehicle operator or service installer) is relatively thin glass, such as with a thickness of about 0.075″ or less. Use of, for example, two substrates, each having a thickness of about 0.075″ or less, for exterior rearview mirrors, including large area mirrors of area greater than about 140 cm², has numerous advantages including reduced weight (reduces vibration and facilitates manually- and electrically-actuated mirror adjustment in the mirror housing), better double-image performance, and more accurate bending for convex/multi-radius parts.

Optionally, on demand displays may be positioned behind the reflective element of the mirror and become activated by user input or by input from a sensor, such as a supplementary vision device (e.g., camera, sensor, proximity detector, blind-spot detector, infrared and microwave detector), temperature sensor, fuel sensor, fault detector, compass sensor, global positioning satellite detector, hazard detector or the like. In addition, a vehicle function (such as a turn signal, hand brake, foot brake, high beam selection, gear change, memory feature selection and the like) may activate the on demand display. The on demand display may also be activated by a function such as a compass, clock, a message center, a speedometer, an engine revolution per unit meter and the like. In the context of their use in conjunction with rearview mirrors for motor vehicles, an on demand display, when not active or activated, should desirably remain at least substantially unobservable or undetectable by the driver and/or passengers. Similarly, in other applications with which these on demand displays may be desirably used, they should remain at least substantially unobservable or undetectable when not activated.

On demand displays should be an emitting electronic display, such as a vacuum fluorescent display, a light emitting diode, a gas discharge display, a plasma display, a cathode ray tube, an electroluminescent display and the like.

If a display is to be mounted behind the reflective element, an appropriately sized and shaped aperture through the auxiliary heating means should be used to accommodate the display but not leave portions of the mirror unheated for de-icing or de-misting purposes Likewise, should a heat distribution pad be used, such as an aluminum or copper foil as described in the '676 application, an appropriately sized and shaped aperture should also be provided therein to accommodate such displays. Where apertures are to be included in a PTC heater pad, a pattern of resistive electrodes which contact the conductive polymer, which may typically be applied by a silk-screening process as described in Friel, should be designed to accommodate the apertures in the pad. In addition, such a pattern may also be useful to thermally compensate for the apertures in the pad. Alternatively, the resistive electrode/conductive polymer combination may be applied, for example, directly onto the rearmost (non-inward) surface of substrate 3, or onto a heat distribution pad that is contacted and/or adhered thereto.

It may also be advantageous to provide mirrors in the form of a module, which module comprises the mirror itself and its electrical connection means (e.g., electrical leads); any heater pad (optionally, including a heat distribution pad) and associated electrical connection means; bezel frames; retaining members (e.g., a one-piece plate) and electrical connection means (see e.g., O'Farrell); actuators [e.g., Model No. H16-49-8001 (right-hand mirror) and Model No. H16-49-8051 (left-hand mirror), commercially available from Matsuyama, Kawoge City, Japan] or planetary-gear actuators [see, U.S. Pat. No. 4,281,899 (Oskamo) and the '947 application] or memory actuators that include memory control circuitry such as Small Electrical Actuator #966/001 which includes a 4 ear adjusting ring, 25 degree travel and an add-on memory control and is available from Industrie Koot B. V. (IKU) of Montfort, Netherlands; and brackets for mounting the module within the casing or housing of a mirror assembly such as taught by and described in the '947 application. Electrochromic mirrors may be assembled using these items to provide modules suitable for use with a mirror casing or housing that includes the electrochromic element, which incorporates the reflective element and any associated components such as heater means, bezel means, electrically or manually operable actuation means, mounting means and electrical connection means. These components may be pre-assembled into a module that is substantially sealed from the outside environment through the use of sealants like silicones, epoxies, epoxides, urethanes and the like. These components may also be formed and/or assembled in an integral molding process, such as with those processes described in U.S. Pat. No. 4,139,234 (Morgan) and U.S. Pat. No. 4,561,625 (Weaver), each of which describe suitable molding processes in the context of modular window encapsulation. An added-value electrochromic mirror module, including the actuators which allow adjustment and selection of reflector field of view when mounted within the outside mirror housings attached to the driver-side and passenger-side of a vehicle, may be pre-assembled and supplied to outside vehicular mirror housing manufacturers to facilitate ease and economy of manufacturing.

Many aspects of the present invention, particularly those relating to the use of PRM and emitting displays; glass cover sheets, foils and the like; and thin film metal coatings that are applied locally and that are substantially reflecting and partially transmitting, may of course be employed with non-electrochromic rearview mirrors for motor vehicles, such as conventional prismatic mirrors. For instance, with exterior rearview mirrors for motor vehicles, a driver-side rearview mirror and a passenger-side rearview mirror may be mounted in combination on a motor vehicle to be used to complement one another and enhance the driver's rearward field of view. One of such mirrors may be an electrochromic mirror and the other mirror may be a non-electrochromic mirror, such as a chromed-glass mirror, with both exterior mirrors benefitting from these aspects of the present invention. In addition, these aspects of the present invention may be employed in connection with a display window that has been established in a prismatic mirror.

Optionally, and as described in U.S. Pat. No. 5,668,663, incorporated above, one or more localized lobe(s) may be provided at appropriate positions along the respective edges of substrates 1402, 1403 to facilitate direct access to the conductive coated inward surfaces of substrates 1402, 1403.

The bus bars may also comprise thin metal films, preferably with a thickness within the range of about 500 Angstroms to about 50,000 Angstroms or greater. These thin metal film bus bars may be deposited onto conductive electrode 1404 and/or 1404′ by vacuum deposition, such as by evaporation or sputtering, and typically have a width within the range of about 0.05 mm to about 6 mm (and preferably with a thickness in the range of 0.05 μm to about 5 μm or greater) and are inboard from the perimeter edge of the substrate.

To form the thin metal film bus bars, a mask may be affixed over the central region of the substantially transparent conductive electrode coated substrate leaving at least a portion, and preferably most, of the perimeter region unmasked. Then a thin film of metal, such as chromium and/or silver, or other metals such as copper, titanium, steel, nickel-based alloys, and the like, may be deposited using a vacuum deposition process across the entire surface, coating both the masked central region and the unmasked perimetal region. Thereafter, the mask may be removed leaving the central region of the substrate transparent and with a conducting thin metal film bus bar deposited on at least a portion of the perimetal region. For manufacturing economy, it may be desirable to establish thin metal film bus bars on the inward surface of substrate 1402, conductive electrode coating 1404′ and electrochromic solid film 1407 in a unitary vacuum deposition process step. Thus, it may be convenient to overlay in central alignment, for example, substrate 1403 (being uncoated glass) onto the substantially transparent conductive electrode coated surface of substrate 1402, where substrate 1403 is sized and shaped about 2 mm to about 4 mm smaller in both length and width than substrate 1402 (see e.g., FIG. 50C). A peripheral edge of substrate 1402 of about 2 mm to about 4 mm will then extend beyond the peripheral edge of substrate 1403. In this instance, substrate 1402 is made, for example, from ITO-coated glass, and substrate 1403 is made from clear soda-lime glass. With this configuration, a vacuum deposition process may be used to deposit a thin metal film and, optionally, a metal oxide thereover, across the entire surface.

Upon completion of the deposition process, the substrates 1402, 1403 may be separated from one another. The formation of a thin metal film bus bar consisting of a chromium/silver coating about the peripheral edge of substrate 1402 may then be seen where, because of its smaller dimensions, substrate 1403 has served the role of a mask to the major, central region of substrate 1402 during deposition. That is, when substrate 1403 is removed, the major, central region of substrate 1402 has not been coated during the deposition and the transparency of the major, central region of substrate 1402 is maintained. Because this thin metal film bus bar is highly conductive and extends about the entire periphery of substrate 1402, electric potential may be supplied by means of a point electrical contact (optionally with local removal of any metal oxide) without the need for a large metal clip or ribbon connector wire as has been conventionally used heretofore. Moreover, because the thin metal film bus bar consists of a chromium/silver coating it forms a highly reflective perimeter coating which may be used to conceal any seal and/or electrical connection for the electrochromic cell [See U.S. Pat. No. 5,066,112 (Lynam)].

In addition, the surface of substrate 1403 which was exposed during deposition is now coated with a chromium/silver/tungsten oxide stack, which may be used as the inward surface in forming an electrochromic cell. The cut edge of substrate 1403 is also coated with a chromium/silver coating during the unitary vacuum deposition process due to the inevitable overspray which occurs in such a process. This chromium/silver coating around the cut edge of substrate 1403 may itself conveniently be used to establish an electrical connection to apply potential to electrochromic solid film 1407.

Optionally, and as described in U.S. Pat. No. 5,668,663, incorporated above, the present teaching is well-suited for use in electrochromic mirrors having a curved functional surface, with a convex curvature, a compound curvature, a multi-radius curvature, aspherical curvature, an aspheric curvature, or combinations of such curvature (See FIG. 52). Convex electrochromic mirrors for motor vehicles may be manufactured with the electrochromic element of the present invention, with radii of curvature typically within the range of about 25″ to about 250″, preferably within the range of about 35″ to about 120″, as are conventionally known.

Multi-radius mirrors for motor vehicles, such as those described in U.S. Pat. No. 4,449,786 (McCord), may also be manufactured in accordance with the present invention. Multi-radius mirrors for motor vehicles may typically be used on the driver-side exterior of a motor vehicle to extend the driver's field of view and to enable the driver to see safely and to avoid blind-spots in the rearward field of view. Generally, such mirrors have a region of a higher radius (i.e., substantially planar or flat) closer or inboard to the driver that serves principally as the primary driver's rear vision function and a region of a lower radius (i.e., more curved) farther or outboard from the driver that serves principally as the blind-spot detection zone in the mirror.

In forming spherical mirrors, such as convex exterior mirrors, or aspherical mirrors such as the multi-radius mirror 1544 in FIG. 52, the radius of curvature for the substrates to be used for the laminate assembly formed by the electrochromic element 1501 between substrates 1502, 1503 should be matched. Moreover, in aspherical mirrors, the two substrates 1502, 1503 in the laminate assembly should be matched so that the local radius in one substrate, for example in the first substrate 1502, is located over, and oriented to align with, its corresponding local radius in the other substrate, for example, in the second substrate 1503 (See FIG. 52).

To achieve such radius of curvature matching, a desired shape for the substrates of the aspherical mirrors may be cut from a flat substrate of dimensions greater than that of the desired multi-radius shape. This initial flat substrate (“a flat minilite”) may have a rectangular, square or circular shape, or may be of the general shape of the desired multi-radius shape, or any other convenient alternative shape. Glass lites from which the flat minilites may be cut are desirably substantially colorless or tinted soda-lime sheets of glass. In addition, depending on the particular mirror construction and whether the desired bent shape derived from the flat minilite is to be employed as the front substrate 1502 or the rear substrate 1503, glass lites/flat minilites, from which the desired bent shape may be derived, may be coated with a substantially transparent conductive electrode coating, such as ITO or fluorine-doped tin oxide. As noted supra, fluorine-doped tin oxide coated glass is commercially available from Libbey-Owens-Ford Co. under the “TEC-Glass” tradename.

Once cut, the oversized flat minilites may be bent to the desired multi-radius using either conventional slump bending or press bending. Also, individual minilites may be bent to compound curvature or two flat minilites may be bent together as a matched pair. To manufacture a matched pair of bent minilites, two flat minilites may be stacked on top of one another, loaded in a tandem orientation into a bending press and bent together to the desired curvature (which may be spherical or aspherical) in one bending process step.

Where individual bent minilites are to be manufactured, any one bent minilite manufactured in any one bending process step is intended to match any other bent minilite. In electrochromic mirrors, it may be advantageous to use the twin bent minilites manufactured in tandem one on top of the other in the one bending operation step as a given matched pair to assemble a laminate construction.

The desired substrates may be cut from bent minilites to the dimension and shape suitable for use in the intended laminate construction of the particular electrochromic mirror. To the extent that the cullet trimmed away from the bent minilite manufactured as described supra conforms least to the intended radius design, bending oversized minilites is recommended. However, and particularly where the bending operation is to be attentively supervised, the desired dimensioned shape may first be cut from flat glass lites, with the desired dimensioned shape then bent to the desired multi-radius curvature.

It may be advantageous to cut multi-radius front and rear substrates from their respective bent minilites to facilitate proper alignment of a local radius on the first substrate relative to its corresponding local radius on the second substrate. In this regard, a matched pair of bent minilites may be assembled into a laminate construction with the first substrate laterally displaced from the second substrate, yet sustaining local to local radius alignment there between. In addition, should there be an asymmetry in radius, one perimeter length, LC, of the bent minilite may be identified as the lower radius (more curved) part of the minilite compared with its opposite perimeter length, LF, identified as the higher radius (more flat) part of that same bent minilite Likewise, for its twin match in a matched pair of bent minilites, there may exist corresponding LC′ and LF′ perimeter lengths.

A demarcation means 1522 may be used in the multi-radius mirrors as described herein to separate the more curved, outboard region 1555 (i.e., that portion of an exterior driver-side multi-radius mirror outboard and farthest from the driver) used by the driver principally as the blind-spot detection zone from the less curved, more flat inboard region 1565 (i.e., closer to the driver) used by the driver principally for the primary rear vision function (See FIG. 52).

The demarcation means 1522 may be a black or darkly colored continuous line or closely interspaced dots, dashes or spots (silk-screened or otherwise applied), which divides the outboard region from the inboard region of the multi-radius mirror. This black or darkly colored dividing line (or its aforestated equivalent) may assist the driver of a motor vehicle to discern the difference between images in the outermost, more curved region from those in the innermost, more flat region of the mirror. The thickness of this dividing line should be within the range of about 0.1 mm to about 3 mm, with about 0.5 mm to about 2 mm being preferred.

The demarcation means 1522 may be constructed from an organic material, such as a polymer like an epoxy; an inorganic material, such as a ceramic frit; or a mixed organic/inorganic material. Such demarcation means 1522 may be constructed to include, for example, an epoxy coupled with glass spacer beads, or plastic tape or a die cut from plastic tape. The demarcation means may be placed onto the conductive electrode coatings 1504, 1504′ of either or both of substrates 1502, 1503 by silk-screening or other suitable technique prior to assembling the device. Also, the demarcation means 1522 may be applied to any or all of the surfaces of substrates 1502, 1503—i.e., the inward surfaces of substrates 1502, 1503 or the opposite, non-inward surfaces of substrates 1502, 1503. Additives may be included in the material used as a demarcation means to provide or enhance color, such as a dark color, like black, or dark blue or dark brown; to enhance stability (e.g., ultraviolet stabilizing agents such as described herein); or to increase adhesion (e.g., coupling agents, such as silane-, titanium-, or zirconium-based coupling agents). Alternatively, a dividing line may be established by etching a surface of substrate 1502 and/or 1503 (such as by sand blasting, laser etching or chemical etching) with optional staining of the etched-surface to develop a dark colored dividing line.

Where ceramic frits are used as a demarcation means and/or where bus bars are formed by applying a silver conductive frit [e.g., #7713 (Du Pont)] around the periphery and inboard from the edge of the inward surface(s) of substrate 1502 and/or substrate 1503, it may be convenient to silk-screen or otherwise apply the material to either or both of the substrates 1502, 1503 prior to bending. In this way, the bending operation serves the dual purpose of bending and firing/curing the ceramic frit onto the substrates. In addition, where epoxies or other organic-based materials are used as the demarcation means and/or materials which act as bus bars, it may be convenient to silk-screen or otherwise apply the material to either or both of the substrates prior to final cure of the material used as the sealing means so that the sealing means, the demarcation means and/or material which acts as bus bars may be fired/cured in one and the same operation step. A dividing line may also be established within the cavity formed between substrates 1502, 1503.

A driver textural warning 1523, such as the conventional textural warning “objects in mirror are closer than they appear”, may be included in the outermost more curved portion 1555 of an electrochromic multi-radius exterior mirror according to this invention (See FIG. 52). Alternatively, a driver textural warning may be included in the innermost less curved region 1565. Heretofore, such warnings have been established through sandblasting or as described in O'Farrell. Alternatively, textural warnings may be applied by silkscreening onto a surface of one of the substrates 1502, 1503 of the mirror assembly or by other suitable techniques, such as laser etching, onto the reflective element of the mirror which is coated onto a surface of substrate 1503.

Therefore, the present invention provides an electro-optic or electrochromic reflective element assembly which requires a minimal bezel or no bezel around the perimeter edges of the reflective element assembly. The reflective element assembly may provide for electrical connection to the conductive layer at the front substrate that is substantially non viewable through the front substrate. The present invention may also provide a reflective element assembly which may provide a flush alignment of the edges of the substrates along at least one side or edge, while providing a relief area for electrical connection to one of the substrates along the flush or aligned edges. The reflective element assembly of the present invention provides enhanced manufacturing of the reflective element assembly, since the flush alignment of the substrates obviates the need for stepped spacers or pins positioned along the upper or lower edges of the substrates during assembly of the reflective element assembly.

Changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law. 

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
 1. An exterior rearview mirror assembly suitable for use for a vehicle, said exterior rearview mirror assembly comprising: a casing portion; wherein said casing portion comprises a variable reflectance mirror reflective element; an attachment portion; wherein said attachment portion is configured for attaching at a side of a vehicle; wherein said mirror reflective element comprises a front substrate and a rear substrate and an electrochromic medium disposed between said front and rear substrates; wherein said front substrate has a first surface and a second surface and wherein a transparent electrically conductive layer is disposed at said second surface of said front substrate; wherein said rear substrate has a third surface and a fourth surface and wherein a mirror reflector is disposed at at least a portion of said third surface of said rear substrate; wherein said mirror reflector comprises a stack of thin films and wherein said stack of thin films comprises at least two thin films; wherein at least one of said thin films is formed of a material that has a specific resistivity of less than about 1×10⁻² ohm·cm; wherein at least one of said thin films comprises a thin metal film; wherein said electrochromic medium is disposed in an interpane cavity between said third surface of said rear substrate and said second surface of said front substrate and is bounded by a perimeter seal; wherein no part of said rear substrate extends beyond any part of said front substrate; wherein a perimeter layer is disposed at said second surface of said front substrate proximate a perimeter edge of said front substrate, and wherein said perimeter layer comprises a reflective perimeter layer; wherein said perimeter layer comprises at least one thin metal film and wherein said perimeter layer is electrically conductive; wherein said perimeter layer generally conceals said perimeter seal from view by a driver of the vehicle normally viewing said front substrate when said exterior rearview mirror assembly is mounted at the vehicle; and wherein said exterior rearview mirror assembly comprises a light source and wherein said light source is at least one of (i) disposed rearward of said mirror reflective element and, when actuated, illuminates through said mirror reflective element, (ii) disposed at said casing portion and (iii) disposed at said attachment portion.
 2. The exterior rearview mirror assembly of claim 1, wherein said light source is disposed at said casing portion.
 3. The exterior rearview mirror assembly of claim 2, wherein said light source comprises a light source of a ground illumination light that, when said light source is actuated, illuminates a ground area generally at the side of the vehicle at which said attachment element is attached when said exterior rearview mirror assembly is mounted at the vehicle.
 4. The exterior rearview mirror assembly of claim 1, wherein said light source is disposed rearward of said mirror reflective element and, when actuated, illuminates through said mirror reflective element.
 5. The exterior rearview mirror assembly of claim 4, wherein said light source, when actuated, illuminates through said mirror reflector of said mirror reflective element.
 6. The exterior rearview mirror assembly of claim 4, wherein said light source comprises a light source of an indicator.
 7. The exterior rearview mirror assembly of claim 6, wherein said indicator, at least when said light source is actuated, is viewable by a driver of the vehicle normally viewing said front substrate when said exterior rearview mirror assembly is mounted at the vehicle.
 8. The exterior rearview mirror assembly of claim 6, wherein said indicator comprises a turn signal indicator.
 9. The exterior rearview mirror assembly of claim 1, wherein said light source is disposed at said attachment portion.
 10. The exterior rearview mirror assembly of claim 9, wherein said light source comprises a light source of a ground illumination light that, when said light source is actuated, illuminates a ground area generally at the side of the vehicle at which said attachment element is attached when said exterior rearview mirror assembly is mounted at the vehicle.
 11. The exterior rearview mirror assembly of claim 1, wherein said light source comprises at least one light emitting diode.
 12. The exterior rearview mirror assembly of claim 1, wherein said casing portion is movable relative to said attachment portion.
 13. The exterior rearview mirror assembly of claim 1, wherein said mirror reflective element is movable relative to said casing portion.
 14. The exterior rearview mirror assembly of claim 13, wherein said light source is disposed rearward of said mirror reflective element and, when actuated, illuminates through said mirror reflective element.
 15. The exterior rearview mirror assembly of claim 1, wherein said material of said at least one of said thin films has a specific resistivity of less than about 1×10⁻³ ohm·cm.
 16. The exterior rearview mirror assembly of claim 15, wherein said material is a metal, and wherein said thin metal film of said at least two thin films of said stack of thin films is formed of said metal.
 17. The exterior rearview mirror assembly of claim 16, wherein said metal has a specific resistivity of less than about 5×10⁻⁴ ohm·cm.
 18. The exterior rearview mirror assembly of claim 17, wherein said metal has a specific resistivity of less than about 5×10⁻⁵ ohm·cm.
 19. The exterior rearview mirror assembly of claim 16, wherein another of said at least two thin films of said stack of films comprises another thin metal film, and wherein said another thin metal film is formed of a metal that has a specific resistivity of less than about 1×10⁻³ ohm·cm.
 20. The exterior rearview mirror assembly of claim 19, wherein said metal of said thin metal film is different from said metal of said another thin metal film.
 21. The exterior rearview mirror assembly of claim 1, wherein at least one of (i) said front substrate has a thickness of about 0.063 inches or less, (ii) said rear substrate has a thickness of about 0.063 inches or less, (iii) said front substrate has a thickness of about 0.063 inches or less and said rear substrate has a thickness of about 0.063 inches or less, (iv) at least one of said front substrate and said rear substrate has a thickness of about 0.043 inches or less, and (v) one of said front substrate and said rear substrate has a thickness of about 0.063 inches or less and the other of said front substrate and said rear substrate has a thickness of about 0.043 inches or less.
 22. The exterior rearview mirror assembly of claim 1, wherein said mirror reflector has a sheet resistance of less than about 5 ohms per square.
 23. The exterior rearview mirror assembly of claim 1, wherein said exterior rearview mirror assembly comprises a driver-side exterior rearview mirror assembly.
 24. The exterior rearview mirror assembly of claim 23, wherein said perimeter seal is at least partially visible to a person viewing through said rear substrate.
 25. The exterior rearview mirror assembly of claim 1, wherein said stack of thin films comprises a spectrally-selective transflective stack of thin films having a multi-band transmission spectrum.
 26. The exterior rearview mirror assembly of claim 1, wherein at least one thin film of said stack of thin films extends beyond said perimeter seal towards said perimeter edge of said rear substrate.
 27. The exterior rearview mirror assembly of claim 1, wherein at least one of (i) one of said thin films has a thickness of at least about 600 angstroms and (ii) said mirror reflector provides at least about 55 percent photopic reflectance measured in accordance with Society of Automotive Engineers test procedure SAE J964a.
 28. The exterior rearview mirror assembly of claim 1, wherein said at least one thin metal film of said perimeter layer comprises chromium.
 29. The exterior rearview mirror assembly of claim 1, wherein said front and rear substrates comprise curved substrates.
 30. The exterior rearview mirror assembly of claim 29, wherein said mirror reflective element comprises a curved mirror reflective element having a more curved outboard region and a less curved inboard region.
 31. The exterior rearview mirror assembly of claim 30, wherein said front and rear substrates comprise aspheric substrates.
 32. The exterior rearview mirror assembly of claim 31, comprising a demarcation that demarcates said more curved outboard region of said mirror reflective element from said less curved inboard region of said mirror reflective element.
 33. The exterior rearview mirror assembly of claim 32, wherein said demarcation comprises one of (i) a continuous line and (ii) closely interspaced dots, dashes and spots.
 34. The exterior rearview mirror assembly of claim 1, wherein said perimeter seal is at least partially visible to a person viewing through said rear substrate.
 35. The exterior rearview mirror assembly of claim 1, wherein light that reflects off of said mirror reflector and passes through said electrochromic medium and said front substrate has a substantially untinted reflectant characteristic to a person normally viewing said front substrate of said mirror reflective element when no voltage is applied to said electrochromic medium.
 36. The exterior rearview mirror assembly of claim 1, wherein an electrically conductive tab portion, which is in electrically conductive contact with said mirror reflector, extends from under said perimeter seal outward towards a portion of said perimeter edge of said rear substrate, and wherein said electrically conductive tab portion at least partially wraps around the edge dimension between said third surface and said fourth surface of said rear substrate at said portion of said perimeter edge of said rear substrate, and wherein an electrical connection is made at said electrically conductive tab portion, and wherein said portion of said perimeter edge of said rear substrate is inward of a corresponding perimeter edge portion of said front substrate.
 37. An exterior rearview mirror assembly suitable for use for a vehicle, said exterior rearview mirror assembly comprising: a casing portion; wherein said casing portion comprises a variable reflectance mirror reflective element; an attachment portion; wherein said attachment portion is configured for attaching at a side of a vehicle; wherein said mirror reflective element comprises a front substrate and a rear substrate and an electrochromic medium disposed between said front and rear substrates; wherein said front substrate has a first surface and a second surface and wherein a transparent electrically conductive layer is disposed at said second surface of said front substrate; wherein said rear substrate has a third surface and a fourth surface and wherein a mirror reflector is disposed at at least a portion of a surface of said rear substrate; wherein said mirror reflector comprises a stack of thin films and wherein said stack of thin films comprises at least a first thin film and a second thin film; wherein said first thin film is formed of a material that has a specific resistivity of less than about 1×10⁻² ohm·cm; wherein said second thin film is formed of a material that has a specific resistivity of less than about 1×10⁻² ohm·cm; wherein said electrochromic medium is disposed in an interpane cavity between said third surface of said rear substrate and said second surface of said front substrate and is bounded by a perimeter seal; wherein no part of said rear substrate extends beyond any part of said front substrate; wherein a perimeter layer is disposed at said second surface of said front substrate proximate a perimeter edge of said front substrate, and wherein said perimeter layer comprises a reflective perimeter layer; wherein said perimeter layer comprises at least one thin metal film and wherein said perimeter layer is electrically conductive; wherein said perimeter layer generally conceals said perimeter seal from view by a driver of the vehicle normally viewing said front substrate when said exterior rearview mirror assembly is mounted at the vehicle; wherein said exterior rearview mirror assembly comprises a light source; wherein said light source comprises at least one light emitting diode; and wherein said light source comprises a light source of an indicator.
 38. The exterior rearview mirror assembly of claim 37, wherein said indicator is disposed at said casing portion.
 39. The exterior rearview mirror assembly of claim 37, wherein said indicator is disposed rearward of said mirror reflective element and, when actuated, illuminates through said mirror reflective element.
 40. The exterior rearview mirror assembly of claim 37, wherein said indicator, at least when said light source is actuated, is viewable by a driver of the vehicle normally viewing said front substrate when said exterior rearview mirror assembly is mounted at the vehicle.
 41. The exterior rearview mirror assembly of claim 37, wherein said indicator comprises a turn signal indicator.
 42. The exterior rearview mirror assembly of claim 37, wherein said material of said first thin film has a specific resistivity of less than about 1×10⁻³ ohm·cm.
 43. The exterior rearview mirror assembly of claim 42, wherein said material of said second thin film has a specific resistivity of less than about 1×10⁻³ ohm·cm.
 44. The exterior rearview mirror assembly of claim 43, wherein said material of said first thin film is a metal and wherein said material of said second thin film is a metal.
 45. The exterior rearview mirror assembly of claim 44, wherein said metal of said first thin film has a specific resistivity of less than about 5×10⁻⁴ ohm·cm and wherein said metal of said second thin film has a specific resistivity of less than about 5×10⁻⁴ ohm·cm.
 46. The exterior rearview mirror assembly of claim 43, wherein said material of said first thin film is different than said material of said second thin film.
 47. The exterior rearview mirror assembly of claim 46, wherein said first thin film comprises a first thin metal film and wherein said second thin film comprises a second thin metal film.
 48. The exterior rearview mirror assembly of claim 47, wherein said mirror reflector is disposed at at least a portion of said third surface of said rear substrate.
 49. The exterior rearview mirror assembly of claim 37, wherein at least one of (i) said front substrate has a thickness of about 0.063 inches or less, (ii) said rear substrate has a thickness of about 0.063 inches or less, (iii) said front substrate has a thickness of about 0.063 inches or less and said rear substrate has a thickness of about 0.063 inches or less, (iv) at least one of said front substrate and said rear substrate has a thickness of about 0.043 inches or less, and (v) one of said front substrate and said rear substrate has a thickness of about 0.063 inches or less and the other of said front substrate and said rear substrate has a thickness of about 0.043 inches or less.
 50. The exterior rearview mirror assembly of claim 37, wherein said mirror reflector has a sheet resistance of less than about 5 ohms per square.
 51. The exterior rearview mirror assembly of claim 37, wherein at least one of (i) said first thin film has a thickness of at least about 600 angstroms and (ii) said mirror reflector provides at least about 55 percent photopic reflectance measured in accordance with Society of Automotive Engineers test procedure SAE J964a.
 52. The exterior rearview mirror assembly of claim 37, wherein said front and rear substrates comprise aspheric substrates, and wherein said mirror reflective element comprises a curved mirror reflective element having a more curved outboard region and a less curved inboard region, and wherein said exterior rearview mirror assembly comprises a demarcation that demarcates said more curved outboard region of said mirror reflective element from said less curved inboard region of said mirror reflective element.
 53. The exterior rearview mirror assembly of claim 37, wherein said perimeter seal is at least partially visible to a person viewing through said rear substrate.
 54. The exterior rearview mirror assembly of claim 37, wherein light that reflects off of said mirror reflector and passes through said electrochromic medium and said front substrate has a substantially untinted reflectant characteristic to a person normally viewing said front substrate of said mirror reflective element when no voltage is applied to said electrochromic medium.
 55. An exterior rearview mirror assembly suitable for use for a vehicle, said exterior rearview mirror assembly comprising: a casing portion; wherein said casing portion comprises a variable reflectance mirror reflective element; an attachment portion; wherein said attachment portion is configured for attaching at a side of a vehicle; wherein said exterior rearview mirror assembly comprises a driver-side exterior rearview mirror assembly; wherein said mirror reflective element comprises a front substrate and a rear substrate and an electrochromic medium disposed between said front and rear substrates; wherein said front substrate has a first surface and a second surface and wherein a transparent electrically conductive layer is disposed at said second surface of said front substrate; wherein said rear substrate has a third surface and a fourth surface and wherein a mirror reflector is disposed at at least a portion of said third surface of said rear substrate; wherein said mirror reflector comprises a stack of thin films and wherein said stack of thin films comprises at least a first thin film and a second thin film; wherein said first thin film is formed of a material that has a specific resistivity of less than about 1×10⁻² ohm·cm; wherein said second thin film is formed of a material that has a specific resistivity of less than about 1×10⁻² ohm·cm; wherein said electrochromic medium is disposed in an interpane cavity between said third surface of said rear substrate and said second surface of said front substrate and is bounded by a perimeter seal; wherein no part of said rear substrate extends beyond any part of said front substrate; wherein a perimeter layer is disposed at said second surface of said front substrate proximate a perimeter edge of said front substrate, and wherein said perimeter layer comprises a reflective perimeter layer; wherein said perimeter layer comprises at least one thin metal film and wherein said perimeter layer is electrically conductive; wherein said perimeter layer generally conceals said perimeter seal from view by a driver of the vehicle normally viewing said front substrate when said exterior rearview mirror assembly is mounted at the vehicle; wherein said mirror reflective element comprises a curved mirror reflective element having a more curved outboard region and a less curved inboard region; a demarcation that demarcates said more curved outboard region of said mirror reflective element from said less curved inboard region of said mirror reflective element; and wherein at least one of (i) said front substrate has a thickness of about 0.063 inches or less, (ii) said rear substrate has a thickness of about 0.063 inches or less, (iii) said front substrate has a thickness of about 0.063 inches or less and said rear substrate has a thickness of about 0.063 inches or less, (iv) at least one of said front substrate and said rear substrate has a thickness of about 0.043 inches or less, and (v) one of said front substrate and said rear substrate has a thickness of about 0.063 inches or less and the other of said front substrate and said rear substrate has a thickness of about 0.043 inches or less.
 56. The exterior rearview mirror assembly of claim 55, wherein said exterior rearview mirror assembly comprises a light source.
 57. The exterior rearview mirror assembly of claim 56, wherein said light source comprises at least one light emitting diode.
 58. The exterior rearview mirror assembly of claim 56, wherein said light source comprises a light source of an indicator.
 59. The exterior rearview mirror assembly of claim 56, wherein said light source comprises a light source of a ground illumination light that, when said light source is actuated, illuminates a ground area generally at the side of the vehicle at which said attachment element is attached when said exterior rearview mirror assembly is mounted at the vehicle.
 60. The exterior rearview mirror assembly of claim 56, wherein said light source comprises a light source of an indicator that is at least one of (i) disposed rearward of said mirror reflective element and, when actuated, illuminates through said mirror reflective element, and (ii) disposed at said casing portion.
 61. The exterior rearview mirror assembly of claim 55, wherein said material of said first thin film has a specific resistivity of less than about 1×10⁻³ ohm·cm.
 62. The exterior rearview mirror assembly of claim 61, wherein said material of said second thin film has a specific resistivity of less than about 1×10⁻³ ohm·cm.
 63. The exterior rearview mirror assembly of claim 62, wherein said material of said first thin film is a metal and wherein said material of said second thin film is a metal.
 64. The exterior rearview mirror assembly of claim 63, wherein said metal of said first thin film has a specific resistivity of less than about 5×10⁻⁴ ohm·cm and wherein said metal of said second thin film has a specific resistivity of less than about 5×10⁻⁴ ohm·cm.
 65. The exterior rearview mirror assembly of claim 63, wherein said metal of said first thin film is different than said metal of said second thin film.
 66. The exterior rearview mirror assembly of claim 55, wherein said first thin film comprises a first thin metal film and wherein said second thin film comprises a second thin metal film.
 67. The exterior rearview mirror assembly of claim 55, wherein said mirror reflector has a sheet resistance of less than about 5 ohms per square.
 68. The exterior rearview mirror assembly of claim 55, wherein at least one of (i) said first thin film has a thickness of at least about 600 angstroms and (ii) said mirror reflector provides at least about 55 percent photopic reflectance measured in accordance with Society of Automotive Engineers test procedure SAE J964a.
 69. The exterior rearview mirror assembly of claim 55, wherein said perimeter seal is at least partially visible to a person viewing through said rear substrate.
 70. The exterior rearview mirror assembly of claim 55, wherein light that reflects off of said mirror reflector and passes through said electrochromic medium and said front substrate has a substantially untinted reflectant characteristic to a person normally viewing said front substrate of said mirror reflective element when no voltage is applied to said electrochromic medium.
 71. The exterior rearview mirror assembly of claim 55, wherein said front and rear substrates comprise aspheric substrates.
 72. An exterior rearview mirror assembly suitable for use for a vehicle, said exterior rearview mirror assembly comprising: a casing portion; wherein said casing portion comprises a variable reflectance mirror reflective element; an attachment portion; wherein said attachment portion is configured for attaching at a side of a vehicle; wherein said mirror reflective element comprises a front substrate and a rear substrate and an electrochromic medium disposed between said front and rear substrates; wherein said front substrate has a first surface and a second surface and wherein a transparent electrically conductive layer is disposed at said second surface of said front substrate; wherein said rear substrate has a third surface and a fourth surface and wherein a mirror reflector is disposed at at least a portion of said third surface of said rear substrate; wherein said mirror reflector comprises a stack of thin films and wherein said stack of thin films comprises at least a first thin metal film and a second thin metal film; wherein said first thin metal film is formed of a metal that has a specific resistivity of less than about 1×10⁻³ ohm·cm; wherein said second thin metal film is formed of a metal that has a specific resistivity of less than about 1×10⁻³ ohm·cm; wherein said electrochromic medium is disposed in an interpane cavity between said third surface of said rear substrate and said second surface of said front substrate and is bounded by a perimeter seal; wherein no part of said rear substrate extends beyond any part of said front substrate; wherein a perimeter layer is disposed at said second surface of said front substrate proximate a perimeter edge of said front substrate, and wherein said perimeter layer comprises a reflective perimeter layer; wherein said perimeter layer comprises at least one thin metal film and wherein said perimeter layer is electrically conductive; wherein said perimeter layer generally conceals said perimeter seal from view by a driver of the vehicle normally viewing said front substrate when said exterior rearview mirror assembly is mounted at the vehicle; wherein said exterior rearview mirror assembly comprises a light source; and wherein light that reflects off of said mirror reflector and passes through said electrochromic medium and said front substrate has a substantially untinted reflectant characteristic to a person normally viewing said front substrate of said mirror reflective element when no voltage is applied to said electrochromic medium.
 73. The exterior rearview mirror assembly of claim 72, wherein said exterior rearview mirror assembly comprises a light source.
 74. The exterior rearview mirror assembly of claim 73, wherein said light source comprises at least one light emitting diode.
 75. The exterior rearview mirror assembly of claim 73, wherein said light source comprises a light source of an indicator.
 76. The exterior rearview mirror assembly of claim 73, wherein said light source comprises a light source of a ground illumination light that, when said light source is actuated, illuminates a ground area generally at the side of the vehicle at which said attachment element is attached when said exterior rearview mirror assembly is mounted at the vehicle.
 77. The exterior rearview mirror assembly of claim 72, wherein said mirror reflector has a sheet resistance of less than about 5 ohms per square.
 78. The exterior rearview mirror assembly of claim 72, wherein said perimeter seal is at least partially visible to a person viewing through said rear substrate.
 79. The exterior rearview mirror assembly of claim 72, wherein said metal of said first thin metal film is different than said metal of said second thin metal film.
 80. The exterior rearview mirror assembly of claim 72, wherein said metal of said first thin film has a specific resistivity of less than about 5×10⁻⁴ ohm·cm and wherein said metal of said second thin film has a specific resistivity of less than about 5×10⁻⁴ ohm·cm.
 81. The exterior rearview mirror assembly of claim 72, wherein said mirror reflective element comprises a curved mirror reflective element having a more curved outboard region and a less curved inboard region.
 82. The exterior rearview mirror assembly of claim 81, comprising a demarcation that demarcates said more curved outboard region of said mirror reflective element from said less curved inboard region of said mirror reflective element.
 83. The exterior rearview mirror assembly of claim 72, wherein at least one of (i) said front substrate has a thickness of about 0.063 inches or less, (ii) said rear substrate has a thickness of about 0.063 inches or less, (iii) said front substrate has a thickness of about 0.063 inches or less and said rear substrate has a thickness of about 0.063 inches or less, (iv) at least one of said front substrate and said rear substrate has a thickness of about 0.043 inches or less, and (v) one of said front substrate and said rear substrate has a thickness of about 0.063 inches or less and the other of said front substrate and said rear substrate has a thickness of about 0.043 inches or less. 